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2014 Volume 30 Issue 4
2014, 30(4): 717-724
doi: 10.11862/CJIC.2014.149
Abstract:
Three cadmium coordination polymers, named as [Cd(AT)(H2O)]n (1), [Cd(AT)(Py)]n (2) and [Cd(AT)(BPP)]n (3) (AT=2-aminoterephthalate, Py=pyridine, BPP=1,3-bi(pyridin-4-yl)propane), have been synthesized based on2-aminoterephthalic acid. The crystal structures indicate that 2-aminoterephthalate exhibits three different coordination modes in these compounds due to different auxiliary ligands, resulting in rtl (1), ths (2) and sql (3) topology, respectively. They display good thermal stability due to intermolecular/intramolecular hydrogen bonding, π…π stacking and C-H…π interactions within the framework.
Three cadmium coordination polymers, named as [Cd(AT)(H2O)]n (1), [Cd(AT)(Py)]n (2) and [Cd(AT)(BPP)]n (3) (AT=2-aminoterephthalate, Py=pyridine, BPP=1,3-bi(pyridin-4-yl)propane), have been synthesized based on2-aminoterephthalic acid. The crystal structures indicate that 2-aminoterephthalate exhibits three different coordination modes in these compounds due to different auxiliary ligands, resulting in rtl (1), ths (2) and sql (3) topology, respectively. They display good thermal stability due to intermolecular/intramolecular hydrogen bonding, π…π stacking and C-H…π interactions within the framework.
2014, 30(4): 725-732
doi: 10.11862/CJIC.2014.125
Abstract:
To improve the electrochemical properties of spinel LiMn2O4 cathode material, LiMn2O4 coated with Al doped ZnO(AZO) was prepared by sol-gel method. The effects of AZO coating on the structural and electrochemical properties were investigated by XRD, SEM, EDS, TEM, EIS, ICP-AES and charge-discharge test. The results demonstrate that AZO coating can effectively obstruct the direct contact between the cathode electrode and electrolyte and suppress the dissolution of manganese into the electrolyte. It is shown that 1.5wt% AZO-coated LiMn2O4 delivers a capacity of 114 mAh·g-1 with a capacity retention of 95.4% after 100 cycles operated at 1C rate and 55 ℃, which is obviously higher than that of bare LiMn2O4 (70.6%). Moreover, 1.5wt% AZO-coated LiMn2O4 presents an excellent high-rate capability with the discharge capacity of 99 mAh·g-1 at 10C rate.
To improve the electrochemical properties of spinel LiMn2O4 cathode material, LiMn2O4 coated with Al doped ZnO(AZO) was prepared by sol-gel method. The effects of AZO coating on the structural and electrochemical properties were investigated by XRD, SEM, EDS, TEM, EIS, ICP-AES and charge-discharge test. The results demonstrate that AZO coating can effectively obstruct the direct contact between the cathode electrode and electrolyte and suppress the dissolution of manganese into the electrolyte. It is shown that 1.5wt% AZO-coated LiMn2O4 delivers a capacity of 114 mAh·g-1 with a capacity retention of 95.4% after 100 cycles operated at 1C rate and 55 ℃, which is obviously higher than that of bare LiMn2O4 (70.6%). Moreover, 1.5wt% AZO-coated LiMn2O4 presents an excellent high-rate capability with the discharge capacity of 99 mAh·g-1 at 10C rate.
2014, 30(4): 733-740
doi: 10.11862/CJIC.2014.151
Abstract:
Rechargeable lithium-sulfur batteries' commercial applications are still hindered by some major basic obstacles, such as the low electrical conductivity of sulfur and polysulfides, the dissolution of lithium polysulfides in organic electrolyte, and the volume expansion of sulfur during discharge. In this study, a mesoporous carbon nanofiber (MCNF) with graphitic pore wall prepared by an easy self-template strategy was designed to encapsulate sulfur and polysulfides in the carbon framework. The one-dimensional MCNF with graphitic pore wall can provide an effective conductive network for sulfur and polysulfides during cycling. The small mesopore of MCNF can also restrain the diffusion of long-chain polysulfides. Furthermore, MNCF with high volume can encapsulate a relatively high amount of sulfur and provide internal void space to accommodate volume expansion during discharge. The resulting MCNF-sulfur nanocomposite shows high and stable specific capacities of 820 mAh·g-1 after 100 cycles at a rate of 0.8 A·g-1.
Rechargeable lithium-sulfur batteries' commercial applications are still hindered by some major basic obstacles, such as the low electrical conductivity of sulfur and polysulfides, the dissolution of lithium polysulfides in organic electrolyte, and the volume expansion of sulfur during discharge. In this study, a mesoporous carbon nanofiber (MCNF) with graphitic pore wall prepared by an easy self-template strategy was designed to encapsulate sulfur and polysulfides in the carbon framework. The one-dimensional MCNF with graphitic pore wall can provide an effective conductive network for sulfur and polysulfides during cycling. The small mesopore of MCNF can also restrain the diffusion of long-chain polysulfides. Furthermore, MNCF with high volume can encapsulate a relatively high amount of sulfur and provide internal void space to accommodate volume expansion during discharge. The resulting MCNF-sulfur nanocomposite shows high and stable specific capacities of 820 mAh·g-1 after 100 cycles at a rate of 0.8 A·g-1.
2014, 30(4): 741-748
doi: 10.11862/CJIC.2014.134
Abstract:
Interfacing "top-down" with "bottom-up" methods to fabricate micro-and nano-devices are one target in nano-science and nano-technology presently. Herein we demonstrate the combination of photolithography and self-assembly to grow DNA nanotubes on functionalized patterns of poly(poly(ethylene glycol)monomethacrylate) brushes grafted from a silicon chip surface (Si-g-Poly(PEGMA)). On the silicon surface, first, the bromoisobutyryl group as the polymerization initiator was introduced through hydrosilylation, then poly(PEGMA) brushes were grown in-situ by Surface Initiated Atom Transfer Radical Polymerization (SI-ATRP), NHS(succinimidyl)-ester was generated on photolithographied poly(PEGMA) patterns and finally six-helix DNA tubes were immobilized and grown in-situ on these patterns. Multiple transmission-reflection infrared spectroscopy (MTR-IR), gel electrophoresis, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to monitor the whole process, which confirmed the feasibility of DNA self-assembly on the functionalized patterns of a silicon chip.
Interfacing "top-down" with "bottom-up" methods to fabricate micro-and nano-devices are one target in nano-science and nano-technology presently. Herein we demonstrate the combination of photolithography and self-assembly to grow DNA nanotubes on functionalized patterns of poly(poly(ethylene glycol)monomethacrylate) brushes grafted from a silicon chip surface (Si-g-Poly(PEGMA)). On the silicon surface, first, the bromoisobutyryl group as the polymerization initiator was introduced through hydrosilylation, then poly(PEGMA) brushes were grown in-situ by Surface Initiated Atom Transfer Radical Polymerization (SI-ATRP), NHS(succinimidyl)-ester was generated on photolithographied poly(PEGMA) patterns and finally six-helix DNA tubes were immobilized and grown in-situ on these patterns. Multiple transmission-reflection infrared spectroscopy (MTR-IR), gel electrophoresis, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to monitor the whole process, which confirmed the feasibility of DNA self-assembly on the functionalized patterns of a silicon chip.
2014, 30(4): 749-756
doi: 10.11862/CJIC.2014.112
Abstract:
Three compounds, [Co2Th4(HC8A)2O2(OH)2(DMF)6](1)、[Ni2Th5(H2C8A)(C8A)O4(OH)2(DMF)5(CH3OH)2](2)、[Zn2Th6(HC8A)(C8A)O5(CH3O)(C3H6NO2)2(DMF)5(CH3OH)](3) (H8C8A=p-tert-butylcalix[8]arene, DMF=N,N-dimethylformide), were obtained by solvothermal method and characterized by single crystal X-ray diffraction, element analysis, and so on. All these three structures are featured by some sandwich-like units which are constructed by two tail-to-tail calix[8]arene molecules and one in-between 3d-5f polynuclear core. All the calix[8]-arene molecules adopt a double-cone conformation, each cone of calix[8]arene molecule bonds one thorium cation by its lower rim, and two cones of one calixarene molecule is connected by some thorium or transition metal atoms. Magnetic measurement indicates that compound 1 exhibits weak ferromagnetic interaction between the metals at low temperature.
Three compounds, [Co2Th4(HC8A)2O2(OH)2(DMF)6](1)、[Ni2Th5(H2C8A)(C8A)O4(OH)2(DMF)5(CH3OH)2](2)、[Zn2Th6(HC8A)(C8A)O5(CH3O)(C3H6NO2)2(DMF)5(CH3OH)](3) (H8C8A=p-tert-butylcalix[8]arene, DMF=N,N-dimethylformide), were obtained by solvothermal method and characterized by single crystal X-ray diffraction, element analysis, and so on. All these three structures are featured by some sandwich-like units which are constructed by two tail-to-tail calix[8]arene molecules and one in-between 3d-5f polynuclear core. All the calix[8]-arene molecules adopt a double-cone conformation, each cone of calix[8]arene molecule bonds one thorium cation by its lower rim, and two cones of one calixarene molecule is connected by some thorium or transition metal atoms. Magnetic measurement indicates that compound 1 exhibits weak ferromagnetic interaction between the metals at low temperature.
2014, 30(4): 757-762
doi: 10.11862/CJIC.2014.044
Abstract:
La2CuO4 nanotubes are successfully synthesized by electro-spinning technology. The structure and morphology of the materials are characterized by XRD, TG-DTA and SEM, respectively. The results show that La2CuO4 nanotubes with an average diameter of 150 nm are obtained after sintering at 700 ℃ for 2 h. The La2CuO4 nanotube forms sufficient connection with each other, and good contact with the electrolyte after sintering at 900 ℃ for 0.5 h. Comparing the results obtained by Electrochemical Impedance Spectroscopy (EIS), it is clearly observed that the nanotube cathode exhibits superior performance than the powder cathode. The area specific resistance (ASR) of the nanotube cathode is 1.03 Ω·cm2 at 700 ℃ in air, whereas for the powder one with the same composition, the ASRis 1.61 Ω·cm2. The oxygen partial pressure measurement indicates that the charge transfer process is the rate-limiting step of the nanotube electrode reactions.
La2CuO4 nanotubes are successfully synthesized by electro-spinning technology. The structure and morphology of the materials are characterized by XRD, TG-DTA and SEM, respectively. The results show that La2CuO4 nanotubes with an average diameter of 150 nm are obtained after sintering at 700 ℃ for 2 h. The La2CuO4 nanotube forms sufficient connection with each other, and good contact with the electrolyte after sintering at 900 ℃ for 0.5 h. Comparing the results obtained by Electrochemical Impedance Spectroscopy (EIS), it is clearly observed that the nanotube cathode exhibits superior performance than the powder cathode. The area specific resistance (ASR) of the nanotube cathode is 1.03 Ω·cm2 at 700 ℃ in air, whereas for the powder one with the same composition, the ASRis 1.61 Ω·cm2. The oxygen partial pressure measurement indicates that the charge transfer process is the rate-limiting step of the nanotube electrode reactions.
2014, 30(4): 763-769
doi: 10.11862/CJIC.2014.052
Abstract:
TiO2 nanomaterial with typital anatase was prepared by hydrothermal method. Asurface modification method was carried out by over layer coating on the surface of TiO2 thin film using Cr(NO3)3. The surface phase and morphology of electrodes were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that a layer of chromium oxide with larger particles was coated on TiO2 thin film and the electrode remains homogeneous porous structure. The current-voltage (I-V) curves revealed that short circuit current and photoelectric transfer efficiency of the optimal modified electrode enhanced by 31.1% and 40.4% respectively more than before. Interface characteristics of cells were discussed using EIS. Seen from the results, the resistance of TiO2/dye/electrolyte interface of modified electrode was much larger than before at the same bias. It is indicated that chromium oxide coating on TiO2 thin film suppressed the charge recombination reactions and improved the performance of DSSCs.
TiO2 nanomaterial with typital anatase was prepared by hydrothermal method. Asurface modification method was carried out by over layer coating on the surface of TiO2 thin film using Cr(NO3)3. The surface phase and morphology of electrodes were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that a layer of chromium oxide with larger particles was coated on TiO2 thin film and the electrode remains homogeneous porous structure. The current-voltage (I-V) curves revealed that short circuit current and photoelectric transfer efficiency of the optimal modified electrode enhanced by 31.1% and 40.4% respectively more than before. Interface characteristics of cells were discussed using EIS. Seen from the results, the resistance of TiO2/dye/electrolyte interface of modified electrode was much larger than before at the same bias. It is indicated that chromium oxide coating on TiO2 thin film suppressed the charge recombination reactions and improved the performance of DSSCs.
2014, 30(4): 770-778
doi: 10.11862/CJIC.2014.047
Abstract:
The LiFePO4-based battery properties were studied by using aluminum foil current collector coated with a conductive carbon film. The main properties of LiFePO4 type battery with 10 Ah capacity were also compared by using common aluminum foil and coating carbon aluminum foil (CCAF) from different providers. The results showed that the using of CCAF current collector not only can improve the cohesiveness between the cathode powder and the current collector but can effectively reduce the contact resistance of the cathode material and the current collector, so as to reduce the direct current resistance (DCR) of the battery, and improve the rate performance of the battery. Compared with using common aluminum foil, the DCR is reduced by about 65% with using the CCAF as current collector. But the specific discharge capacity of cathode material is reduced by 5~10 mAh·g-1. And the 1st efficiency is also reduced by 4%; At large discharge rate of 15C rate, the discharge capacity of the cell with using CCAF is more than about 15% in contrast to the cell with common aluminum foil as a current collector. And at 10Cdischarge rate, the voltage plateau increased by 0.3~0.4 V with CCAF; But the self-discharge ratio of cell with CCAF is higher at room temperature, and its recovery rate of the capacity is also higher; After 500 cycles, the cyclic capability of the cell with using CCAFcan increase by about 2% in contrast to the cell with the common aluminum foil as current collector. But the discharge property at low temperature is not improved by the use of CCAF as current collector.
The LiFePO4-based battery properties were studied by using aluminum foil current collector coated with a conductive carbon film. The main properties of LiFePO4 type battery with 10 Ah capacity were also compared by using common aluminum foil and coating carbon aluminum foil (CCAF) from different providers. The results showed that the using of CCAF current collector not only can improve the cohesiveness between the cathode powder and the current collector but can effectively reduce the contact resistance of the cathode material and the current collector, so as to reduce the direct current resistance (DCR) of the battery, and improve the rate performance of the battery. Compared with using common aluminum foil, the DCR is reduced by about 65% with using the CCAF as current collector. But the specific discharge capacity of cathode material is reduced by 5~10 mAh·g-1. And the 1st efficiency is also reduced by 4%; At large discharge rate of 15C rate, the discharge capacity of the cell with using CCAF is more than about 15% in contrast to the cell with common aluminum foil as a current collector. And at 10Cdischarge rate, the voltage plateau increased by 0.3~0.4 V with CCAF; But the self-discharge ratio of cell with CCAF is higher at room temperature, and its recovery rate of the capacity is also higher; After 500 cycles, the cyclic capability of the cell with using CCAFcan increase by about 2% in contrast to the cell with the common aluminum foil as current collector. But the discharge property at low temperature is not improved by the use of CCAF as current collector.
2014, 30(4): 779-785
doi: 10.11862/CJIC.2014.153
Abstract:
Based on the various functional groups of graphite oxide, the influence of reduction temperature on structures and humidity sensitivity of graphite oxide has been studied. High oxidized graphene oxide samples prepared by modified Hummers method were reduced at different temperature. And the humidity sensors were made with the reduction products. Functional groups and structures changes of the experiment process samples were carried out by FTIR, XRD and Raman spectrum. The results show that functional groups of -OH, epoxy group, C=O and COOH were combined with the structure layer of carbon atoms during oxidation process. And the basal spacing of graphite oxide is about 0.9084 nm. As the increase of reduction temperature, functional groups were gradually thermal decomposition and the graphitization area gradually restored, but the relative sizes were decreased and the defects were increased. Furthermore, the basal spacing of graphite oxide was decreased from 0.9084 nm to 0.4501 nm along the c axis. The resistances of the graphite oxide thin film were decreased from 10.32 MΩ to 41.1 Ω. In the relative humidity of 11.3%~93.6%, the resistance of the graphite oxide thin film humidity elements was significantly reduced with increasing of humidity. The higher of the reduction degree was, the longer of element's response time was and the shorter of the element's desorption time was. The graphite oxide film humidity element of 150 ℃ reduction was the best humidity sensitive performance.
Based on the various functional groups of graphite oxide, the influence of reduction temperature on structures and humidity sensitivity of graphite oxide has been studied. High oxidized graphene oxide samples prepared by modified Hummers method were reduced at different temperature. And the humidity sensors were made with the reduction products. Functional groups and structures changes of the experiment process samples were carried out by FTIR, XRD and Raman spectrum. The results show that functional groups of -OH, epoxy group, C=O and COOH were combined with the structure layer of carbon atoms during oxidation process. And the basal spacing of graphite oxide is about 0.9084 nm. As the increase of reduction temperature, functional groups were gradually thermal decomposition and the graphitization area gradually restored, but the relative sizes were decreased and the defects were increased. Furthermore, the basal spacing of graphite oxide was decreased from 0.9084 nm to 0.4501 nm along the c axis. The resistances of the graphite oxide thin film were decreased from 10.32 MΩ to 41.1 Ω. In the relative humidity of 11.3%~93.6%, the resistance of the graphite oxide thin film humidity elements was significantly reduced with increasing of humidity. The higher of the reduction degree was, the longer of element's response time was and the shorter of the element's desorption time was. The graphite oxide film humidity element of 150 ℃ reduction was the best humidity sensitive performance.
2014, 30(4): 786-792
doi: 10.11862/CJIC.2014.124
Abstract:
Two isomorphous coordination polymers, {[Ln2(pda)3(H2O)2)·2H2O}n (Ln=Nd(1), La(2)), have been hydrothermally synthesized by reaction of rare-earth oxides and o-phenylenediacetic acid (H2pda). The two compounds have been characterized by X-ray single-crystal diffraction, infrared spectroscopy, fluorescence spectroscopy and TG analysis. Crystal structure determination shows that both two compounds crystallized in monoclinic, space group C2/c. Crystallographic parameters for complex 1, a=2.62906(18) nm, b=1.61172(11) nm, c=0.78327(5) nm, β=93.173(5)°, V=3.3139(4) nm3, Z=4, F(000)=1840, μ=3.173 mm-1, Dc=1.878 g·cm-3, R1=0.0226, wR2=0.0609; complex 2, a=2.6271(14) nm, b=1.6149(8) nm, c=0.7966(4) nm, β=92.850(9)°, V=3.3139(4) nm3, Z=4, F(000)=1816, μ=2.570 mm-1, Dc=1.823 g·cm-3, R1=0.0466, wR2=0.1416. In the two compounds, neighboring lanthanide ions are connected by o-phenylenediacetate to form 3D networks with stp topology. TG and FL analysis indicate that both compounds have good thermal stability and compound 2 exhibits emission in the solid state at room temperature.
Two isomorphous coordination polymers, {[Ln2(pda)3(H2O)2)·2H2O}n (Ln=Nd(1), La(2)), have been hydrothermally synthesized by reaction of rare-earth oxides and o-phenylenediacetic acid (H2pda). The two compounds have been characterized by X-ray single-crystal diffraction, infrared spectroscopy, fluorescence spectroscopy and TG analysis. Crystal structure determination shows that both two compounds crystallized in monoclinic, space group C2/c. Crystallographic parameters for complex 1, a=2.62906(18) nm, b=1.61172(11) nm, c=0.78327(5) nm, β=93.173(5)°, V=3.3139(4) nm3, Z=4, F(000)=1840, μ=3.173 mm-1, Dc=1.878 g·cm-3, R1=0.0226, wR2=0.0609; complex 2, a=2.6271(14) nm, b=1.6149(8) nm, c=0.7966(4) nm, β=92.850(9)°, V=3.3139(4) nm3, Z=4, F(000)=1816, μ=2.570 mm-1, Dc=1.823 g·cm-3, R1=0.0466, wR2=0.1416. In the two compounds, neighboring lanthanide ions are connected by o-phenylenediacetate to form 3D networks with stp topology. TG and FL analysis indicate that both compounds have good thermal stability and compound 2 exhibits emission in the solid state at room temperature.
2014, 30(4): 793-799
doi: 10.11862/CJIC.2014.136
Abstract:
Yttrium doped SiO2 monolithic aerogels were prepared with YCl3·6H2O, TEOS as raw material by sol-gel method and CO2 supercritical drying technique, and the doping concentrations are in the range of 5wt%~30wt% Y2O3. The structures and properties of samples were analyzed by means of SEM (Scanning electron microscope), TEM (Transmission electron microscope), XRD (X-ray diffraction), BET (Brunauer-Emmett-Teller) and XRF (X-ray fluorescence). The results showed that Y2O3-SiO2 aerogels maintained the original space network structures of SiO2 aerogels. Improvements in thermal stability were obtained by incorporation of yttrium species during the aerogels preparation. When treated by the thermal treatment with 900 ℃ for 2 h, the 10wt% (0.447 g of YCl3·6H2O)Y2O3-SiO2 aerogels still showed an amorphous state and gave a larger surface area of 643.79 m2·g-1,and the average pore diameter was about 21.3 nm.
Yttrium doped SiO2 monolithic aerogels were prepared with YCl3·6H2O, TEOS as raw material by sol-gel method and CO2 supercritical drying technique, and the doping concentrations are in the range of 5wt%~30wt% Y2O3. The structures and properties of samples were analyzed by means of SEM (Scanning electron microscope), TEM (Transmission electron microscope), XRD (X-ray diffraction), BET (Brunauer-Emmett-Teller) and XRF (X-ray fluorescence). The results showed that Y2O3-SiO2 aerogels maintained the original space network structures of SiO2 aerogels. Improvements in thermal stability were obtained by incorporation of yttrium species during the aerogels preparation. When treated by the thermal treatment with 900 ℃ for 2 h, the 10wt% (0.447 g of YCl3·6H2O)Y2O3-SiO2 aerogels still showed an amorphous state and gave a larger surface area of 643.79 m2·g-1,and the average pore diameter was about 21.3 nm.
2014, 30(4): 800-804
doi: 10.11862/CJIC.2014.143
Abstract:
A 2Dcoordination polymer [Zn(5-ana)2]n(1), based on a rigid ligand 5-ana(5-anaH=5-aminonicotinic acid)has been synthesized by hydrothermal method and characterized by elemental analysis, IR spectra, TGA, XRD, and the crystal structure was determined by single-crystal X-ray diffraction. The coordination polymer crystallizes in the orthorhombic system, space group P212121, and features 2D layer structure. Second harmonic generation efficiency and fluorescence of the coordination polymer are also further investigated. The results show that this coordination polymer has a second harmonic generation, which can be used as a second-order nonlinear optical material. Fluorescence of the coordination polymer exhibits a blue shift compared with free ligand.
A 2Dcoordination polymer [Zn(5-ana)2]n(1), based on a rigid ligand 5-ana(5-anaH=5-aminonicotinic acid)has been synthesized by hydrothermal method and characterized by elemental analysis, IR spectra, TGA, XRD, and the crystal structure was determined by single-crystal X-ray diffraction. The coordination polymer crystallizes in the orthorhombic system, space group P212121, and features 2D layer structure. Second harmonic generation efficiency and fluorescence of the coordination polymer are also further investigated. The results show that this coordination polymer has a second harmonic generation, which can be used as a second-order nonlinear optical material. Fluorescence of the coordination polymer exhibits a blue shift compared with free ligand.
2014, 30(4): 805-810
doi: 10.11862/CJIC.2014.128
Abstract:
In liquid-solid-solution (LSS) method, when NaOH in the traditional oleic acid/sodium oleate/alcohol reaction system was replaced by ammonia, ammonia reacted with oleic acid, and then a new kind surfactant generated. So, this method can be used to synthesize monodispersed ultrasmall REF3 nanocrystals. In this new reaction system, ultrasmall YF3 and GdF3 nanocrystals have been synthesized. X-ray diffraction (XRD) and transmission electron microscopy (TEM) assays revealed that the as-synthesized YF3 was orthorhombic structure, but GdF3 was face-centered cubic phase (S. G.: Fm3m, lattice constant: 0.5829 nm). Under the excitation of 980 nm diode laser, strong green photoluminescence at 515~570 nm and strong red emission at 645~675 nm of YF3:Yb/Er were detected, so the luminescent color of YF3:Yb/Er nanocrystals presented orange. Intense blue emission peaks at 460~490 nm from YF3:Yb/Tm and GdF3:Yb/Tm nanocrystals were detected, especially the stronger near-infrared photoluminescence peaks near 800 nm. For the ultrasmall size and its relative strong upconversion luminescence, the as-synthesized samples show potential applications in bioimaging, biolabels and etc.
In liquid-solid-solution (LSS) method, when NaOH in the traditional oleic acid/sodium oleate/alcohol reaction system was replaced by ammonia, ammonia reacted with oleic acid, and then a new kind surfactant generated. So, this method can be used to synthesize monodispersed ultrasmall REF3 nanocrystals. In this new reaction system, ultrasmall YF3 and GdF3 nanocrystals have been synthesized. X-ray diffraction (XRD) and transmission electron microscopy (TEM) assays revealed that the as-synthesized YF3 was orthorhombic structure, but GdF3 was face-centered cubic phase (S. G.: Fm3m, lattice constant: 0.5829 nm). Under the excitation of 980 nm diode laser, strong green photoluminescence at 515~570 nm and strong red emission at 645~675 nm of YF3:Yb/Er were detected, so the luminescent color of YF3:Yb/Er nanocrystals presented orange. Intense blue emission peaks at 460~490 nm from YF3:Yb/Tm and GdF3:Yb/Tm nanocrystals were detected, especially the stronger near-infrared photoluminescence peaks near 800 nm. For the ultrasmall size and its relative strong upconversion luminescence, the as-synthesized samples show potential applications in bioimaging, biolabels and etc.
2014, 30(4): 811-820
doi: 10.11862/CJIC.2014.089
Abstract:
The Pr2Zr2O7 nanoparticles were prepared by using NSC and RSC co-precipitation method with ammonia as precipitant agent. XRD, SEM, TEM and TG-DTA were applied to analysis the crystallization and morphology of the samples. Synthesis kinetics of the preparation process and dynamics of grain growth were studied, and the apparent activation energy was calculated respectively by using Doyle-Ozawa method and the Kissinger method. The results show that the samples topography near spherical, there are no agglomeration and the mean particle size is about 60nm. They were obtained under the conditions of titration rate, 2 mL·min-1, initial concentration of resolution, 0.05 mol·L-1, system temperature 273K and calcination at 1173 K for 2 h by RSC. The average apparent activation energy of the particles, obtained by NSC, were 71.2, 97.8 and 183.2 kJ·mol-1 in each stage and the RSCs were 45.37, 84.34 and 152.16 kJ·mol-1; the grain growth activation energy of them were 19.02 and 11.95 kJ·mol-1 respectively, the latter decreases 7.07 kJ·mol-1 than the former. Reverse co-precipitation preparation technology is better than that of positive co-precipitation method.
The Pr2Zr2O7 nanoparticles were prepared by using NSC and RSC co-precipitation method with ammonia as precipitant agent. XRD, SEM, TEM and TG-DTA were applied to analysis the crystallization and morphology of the samples. Synthesis kinetics of the preparation process and dynamics of grain growth were studied, and the apparent activation energy was calculated respectively by using Doyle-Ozawa method and the Kissinger method. The results show that the samples topography near spherical, there are no agglomeration and the mean particle size is about 60nm. They were obtained under the conditions of titration rate, 2 mL·min-1, initial concentration of resolution, 0.05 mol·L-1, system temperature 273K and calcination at 1173 K for 2 h by RSC. The average apparent activation energy of the particles, obtained by NSC, were 71.2, 97.8 and 183.2 kJ·mol-1 in each stage and the RSCs were 45.37, 84.34 and 152.16 kJ·mol-1; the grain growth activation energy of them were 19.02 and 11.95 kJ·mol-1 respectively, the latter decreases 7.07 kJ·mol-1 than the former. Reverse co-precipitation preparation technology is better than that of positive co-precipitation method.
2014, 30(4): 821-827
doi: 10.11862/CJIC.2014.094
Abstract:
The graphitic-like carbon nitride (C3N4) and graphene oxide (GO) were respectively prepared by one step semi-enclosed pyrolysis and improved Hummers method. Following the reduced graphene oxide/C3N4 (RGO/C3N4) composites were fabricated via a photo-reduction route. The as-prepared samples were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance absorption spectroscopy (DRS), Photoluminescence (PL) and Fourier transform infrared spectroscopy (FTIR). The photocatalytic activity of samples was evaluated under visible light irradiation using Rhodamine B(RhB) as probe molecule. The experimental results show that the introduction of RGO could considerably enhance photocatalytic activity, and the 6.0% RGO/C3N4 composite exhibits the best photocatalytic performance. The significantly enhanced photocatalytic activity for the present composite originates from the electron-accepting and electron-transportation property of RGO, which inhibits the recombination rate of photogenerated electron-hole pairs.
The graphitic-like carbon nitride (C3N4) and graphene oxide (GO) were respectively prepared by one step semi-enclosed pyrolysis and improved Hummers method. Following the reduced graphene oxide/C3N4 (RGO/C3N4) composites were fabricated via a photo-reduction route. The as-prepared samples were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance absorption spectroscopy (DRS), Photoluminescence (PL) and Fourier transform infrared spectroscopy (FTIR). The photocatalytic activity of samples was evaluated under visible light irradiation using Rhodamine B(RhB) as probe molecule. The experimental results show that the introduction of RGO could considerably enhance photocatalytic activity, and the 6.0% RGO/C3N4 composite exhibits the best photocatalytic performance. The significantly enhanced photocatalytic activity for the present composite originates from the electron-accepting and electron-transportation property of RGO, which inhibits the recombination rate of photogenerated electron-hole pairs.
2014, 30(4): 828-836
doi: 10.11862/CJIC.2014.099
Abstract:
In this paper, Ginkgo-like PbWO4 has been synthesized using direct precipitation method, taking sodium tartrate as the surfactant. The structure and property of synthesized products have been characterized by combination of scanning electron microscope (SEM), X-ray power diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and fluorescence emission spectra (PL). Investigations were carried out on the sodium tartrates inhibitory effect on the crystal face(004), and the impact of pHvalue and aging temperature on products morphology. Aprobable mechanism for products formation is proposed based on the internal crystal structure analysis. The results indicated that the most uniform crystal morphology will be obtained at the aging temperature of 30 ℃. PbWO4 crystal presented intense green emission under ultraviolet excitation, which will reach a maximum luminous intensity at pH=9.
In this paper, Ginkgo-like PbWO4 has been synthesized using direct precipitation method, taking sodium tartrate as the surfactant. The structure and property of synthesized products have been characterized by combination of scanning electron microscope (SEM), X-ray power diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and fluorescence emission spectra (PL). Investigations were carried out on the sodium tartrates inhibitory effect on the crystal face(004), and the impact of pHvalue and aging temperature on products morphology. Aprobable mechanism for products formation is proposed based on the internal crystal structure analysis. The results indicated that the most uniform crystal morphology will be obtained at the aging temperature of 30 ℃. PbWO4 crystal presented intense green emission under ultraviolet excitation, which will reach a maximum luminous intensity at pH=9.
2014, 30(4): 837-844
doi: 10.11862/CJIC.2014.129
Abstract:
Intercalation of dodecyl benzene sulphonate (DBS) and sulfobutyl ether β-cyclodextrin (SBE-β-CD) into layered zinc hydroxide nitrate (Zn-LHS) and nickel/zinc hydroxide nitrate (NiZn-LHS) was synthesized by coprecipitation and ion-exchanged methods. The effect of anion concentration and pHvalue on preparation was systematically investigated and compared. The products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry and differential thermal analysis (TG-DTA), and scanning electron microscope (SEM). The results showed that Zn-LHS-DBS with pure phase and good crystallinity was obtained at DBS concentration of 0.19~0.38 mol·L-1, pH=6.0~7.0, temperature of hydrothermal treatment of 60~100 ℃ by coprecipitation method. The NiZn-LHS-SBE-β-CD with good structure was prepared by ion-exchanged method. Zn-LHS-SBE-β-CD with pure phase was not successfully prepared by both coprecipitation and ion-exchanged method due to the particular structure of SBE-β-CD and poor hydrothermal stability of Zn-LHS. Furthermore, TG-DTA data indicated that stability of SBE-β-CD and DBSimproved distinctly in the interlayer due to the strong supra-molecular interaction existed between anions and hostlayer of LHS.
Intercalation of dodecyl benzene sulphonate (DBS) and sulfobutyl ether β-cyclodextrin (SBE-β-CD) into layered zinc hydroxide nitrate (Zn-LHS) and nickel/zinc hydroxide nitrate (NiZn-LHS) was synthesized by coprecipitation and ion-exchanged methods. The effect of anion concentration and pHvalue on preparation was systematically investigated and compared. The products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry and differential thermal analysis (TG-DTA), and scanning electron microscope (SEM). The results showed that Zn-LHS-DBS with pure phase and good crystallinity was obtained at DBS concentration of 0.19~0.38 mol·L-1, pH=6.0~7.0, temperature of hydrothermal treatment of 60~100 ℃ by coprecipitation method. The NiZn-LHS-SBE-β-CD with good structure was prepared by ion-exchanged method. Zn-LHS-SBE-β-CD with pure phase was not successfully prepared by both coprecipitation and ion-exchanged method due to the particular structure of SBE-β-CD and poor hydrothermal stability of Zn-LHS. Furthermore, TG-DTA data indicated that stability of SBE-β-CD and DBSimproved distinctly in the interlayer due to the strong supra-molecular interaction existed between anions and hostlayer of LHS.
2014, 30(4): 845-852
doi: 10.11862/CJIC.2014.090
Abstract:
Li0.35Zn0.3Fe2.35O4 and carbon nanofibers with average diameters of 160 and 360 nm, respectively, were fabricated by electrospinning technique combined with subsequent heat treatment. By dispersing the nanofibers homogeneously into a silicone rubber matrix, the relative complex permittivity and permeability of the composites containing either 60wt% Li0.35Zn0.3Fe2.35O4 nanofibers or 5wt% carbon nanofibers as fillers were measured in the frequency range of 2~18 GHz. Electromagnetic wave absorbing performance of both single-layer and double-layer microwave absorbers was evaluated according to transmission line theory. It is found that the double-layer absorbers have much better microwave absorption properties than the single-layer absorbers with the same thickness due to the proper combination of the electromagnetic characteristics resulting from the magnetic Li0.35Zn0.3Fe2.35O4 nanofibers and dielectric carbon nanofibers. When the absorbing layer is the Li0.35Zn0.3Fe2.35O4 nanofibers/silicone rubber composite with a thickness of 1.8 mm and the matching layer is the carbon nanofibers/silicone rubber composite with a thickness of 0.2 mm, the refection loss (RL) of the double-layer absorber reaches a minimum value of -47.8 dBat around 13.9 GHz and the absorption bandwidth with the RLvalue below -10 dBis about 8.8 GHz ranging from 9.2~18 GHz. Meanwhile, the RLvalue exceeding -20 dBis obtained over the range of 11.5~18 GHz, which covers the whole Ku-band. The results indicate that the optimal double-layer microwave absorbers can be a promising candidate for lightweight and highly effective microwave absorption materials in Ku-band.
Li0.35Zn0.3Fe2.35O4 and carbon nanofibers with average diameters of 160 and 360 nm, respectively, were fabricated by electrospinning technique combined with subsequent heat treatment. By dispersing the nanofibers homogeneously into a silicone rubber matrix, the relative complex permittivity and permeability of the composites containing either 60wt% Li0.35Zn0.3Fe2.35O4 nanofibers or 5wt% carbon nanofibers as fillers were measured in the frequency range of 2~18 GHz. Electromagnetic wave absorbing performance of both single-layer and double-layer microwave absorbers was evaluated according to transmission line theory. It is found that the double-layer absorbers have much better microwave absorption properties than the single-layer absorbers with the same thickness due to the proper combination of the electromagnetic characteristics resulting from the magnetic Li0.35Zn0.3Fe2.35O4 nanofibers and dielectric carbon nanofibers. When the absorbing layer is the Li0.35Zn0.3Fe2.35O4 nanofibers/silicone rubber composite with a thickness of 1.8 mm and the matching layer is the carbon nanofibers/silicone rubber composite with a thickness of 0.2 mm, the refection loss (RL) of the double-layer absorber reaches a minimum value of -47.8 dBat around 13.9 GHz and the absorption bandwidth with the RLvalue below -10 dBis about 8.8 GHz ranging from 9.2~18 GHz. Meanwhile, the RLvalue exceeding -20 dBis obtained over the range of 11.5~18 GHz, which covers the whole Ku-band. The results indicate that the optimal double-layer microwave absorbers can be a promising candidate for lightweight and highly effective microwave absorption materials in Ku-band.
2014, 30(4): 853-859
doi: 10.11862/CJIC.2014.102
Abstract:
Anew method using gel filtration chromatography (GFC) and inductively coupled plasma mass spectrometry (ICPMS) was developed for the measurement of complexation stability constant and average coordination number of the complex of metallic ion with polymer. As an example, the binding of PEI with Cu2+ was shown and investigated. The macromolecular PEI-Cu complex and micromolecular species of Cu(Ⅱ) were firstly separated by a low efficiency GFC column with a mobile phase of 0.02 mol·L-1 HAc-NaAc buffer, and then directly introduced into ICPMS for elemental analysis. The results of complexation stability constant and average coordination number characterized by putting the concentration of different species of metallic element into the equations of the novel chemical equilibrium model which was developed in this study. The results shown that the complexation stability constants (KPEI-Cu) were between 109.6 and 1010.7 and the average coordination numbers (n) were in the range of 1.0~1.3 when pHwas changed from 4.1 to 5.3 at 25 ℃. This online, rapid and accurate method of GFC-ICPMS is a novel technique for the research of polymer-metallic complex.
Anew method using gel filtration chromatography (GFC) and inductively coupled plasma mass spectrometry (ICPMS) was developed for the measurement of complexation stability constant and average coordination number of the complex of metallic ion with polymer. As an example, the binding of PEI with Cu2+ was shown and investigated. The macromolecular PEI-Cu complex and micromolecular species of Cu(Ⅱ) were firstly separated by a low efficiency GFC column with a mobile phase of 0.02 mol·L-1 HAc-NaAc buffer, and then directly introduced into ICPMS for elemental analysis. The results of complexation stability constant and average coordination number characterized by putting the concentration of different species of metallic element into the equations of the novel chemical equilibrium model which was developed in this study. The results shown that the complexation stability constants (KPEI-Cu) were between 109.6 and 1010.7 and the average coordination numbers (n) were in the range of 1.0~1.3 when pHwas changed from 4.1 to 5.3 at 25 ℃. This online, rapid and accurate method of GFC-ICPMS is a novel technique for the research of polymer-metallic complex.
2014, 30(4): 860-866
doi: 10.11862/CJIC.2014.091
Abstract:
The flame retardant magnesium hydroxide powder was prepared by two-step method using magnesium oxide which was calcined by magnesium chloride as raw material. Two-step method consists of hydrating and hydrothermal reaction process. The effects of hydration time, hydrothermal reaction time and temperature, and the concentration of sodium hydroxide on the morphology and structure of magnesium hydroxide had been studied. Special attention was given to the obtaining of platelet-shaped, high purity and highly-dispersible powders. The characterization of magnesium hydroxide powder was investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and nitrogen absorption BET analyzer. It is indicated that magnesium oxide has been completely hydrated after 3h. As the hydrothermal temperature and time increased, crystal size became larger and crystalline dispersion became remarkable. Additionally, increasing the hydrothermal additives concentration of sodium hydroxide can significantly improve the degree of crystallization crystals, reduce the microscopic internal strain of crystal, and enhance powder dispersibility.
The flame retardant magnesium hydroxide powder was prepared by two-step method using magnesium oxide which was calcined by magnesium chloride as raw material. Two-step method consists of hydrating and hydrothermal reaction process. The effects of hydration time, hydrothermal reaction time and temperature, and the concentration of sodium hydroxide on the morphology and structure of magnesium hydroxide had been studied. Special attention was given to the obtaining of platelet-shaped, high purity and highly-dispersible powders. The characterization of magnesium hydroxide powder was investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and nitrogen absorption BET analyzer. It is indicated that magnesium oxide has been completely hydrated after 3h. As the hydrothermal temperature and time increased, crystal size became larger and crystalline dispersion became remarkable. Additionally, increasing the hydrothermal additives concentration of sodium hydroxide can significantly improve the degree of crystallization crystals, reduce the microscopic internal strain of crystal, and enhance powder dispersibility.
2014, 30(4): 867-871
doi: 10.11862/CJIC.2014.126
Abstract:
Pt/C catalyst with the different Pt particles sizes were prepared with the organic sol method, which was synthesized in a methanol solution by chemical reduction of the corresponding metal salts using SnCl2 as reducing agent. The catalysts which have different average size, great uniformity and high distribution of the metal particles were prepared by controlling the reacting condition. It was electrochemically proved that the effect of average particle size of ultrafine platinum particles for oxygen reduction was obvious. When the average particle size of Pt is 3.2 nm, the mass activity of the Pt/C catalysts for the oxygen reduction is the best. This effect may be related to the quantity of the oxygen-containing species on it, the apparent surface area of the platinum particles and the crystal structure.
Pt/C catalyst with the different Pt particles sizes were prepared with the organic sol method, which was synthesized in a methanol solution by chemical reduction of the corresponding metal salts using SnCl2 as reducing agent. The catalysts which have different average size, great uniformity and high distribution of the metal particles were prepared by controlling the reacting condition. It was electrochemically proved that the effect of average particle size of ultrafine platinum particles for oxygen reduction was obvious. When the average particle size of Pt is 3.2 nm, the mass activity of the Pt/C catalysts for the oxygen reduction is the best. This effect may be related to the quantity of the oxygen-containing species on it, the apparent surface area of the platinum particles and the crystal structure.
2014, 30(4): 872-878
doi: 10.11862/CJIC.2014.159
Abstract:
Afluorescence enhancement probe WNfor detection of Zn2+ with receptor based on di-2-picolylamine (DPA) was synthesized and structurally characterized. Its recognition properties with Zn2+ had been investigated in CH3CH2OH/Tris-HCl buffer solution (1:9, V/V, pH=7.4). The results showed that WN exhibited good sensitivity and selectivity to Zn2+, and the stoichiometry of WN-Zn2+ complex was estimated to be 1:1, the detection limit of Zn2+ was estimated to be 1.14×10-8 mol·L-1. WN was used for fast visual detection of Zn2+ and its intracelluar Zn2+ imaging in living HeLa cells, indicated that it could be applied in biological detection.
Afluorescence enhancement probe WNfor detection of Zn2+ with receptor based on di-2-picolylamine (DPA) was synthesized and structurally characterized. Its recognition properties with Zn2+ had been investigated in CH3CH2OH/Tris-HCl buffer solution (1:9, V/V, pH=7.4). The results showed that WN exhibited good sensitivity and selectivity to Zn2+, and the stoichiometry of WN-Zn2+ complex was estimated to be 1:1, the detection limit of Zn2+ was estimated to be 1.14×10-8 mol·L-1. WN was used for fast visual detection of Zn2+ and its intracelluar Zn2+ imaging in living HeLa cells, indicated that it could be applied in biological detection.
2014, 30(4): 879-884
doi: 10.11862/CJIC.2014.110
Abstract:
Cobaltous complexes catalyzing the oxidation of water are meaningful to the development of clean energy and new oxidation reaction. Anew ligand of 3-((bis(pyridin-2-ylmethyl)amino)methyl)phenyl)(3,5-dimethyl-1H-pyrrol-2-yl)methanone and the cobaltous complex (Co1) were synthesized and characterized by IR, UV, NMR, ES-MS, et al. methods. The oxidation of water catalyzed by Co1 in aqueous solution was studied. Results show that the complex Co1 can catalyze the oxidation of water to release the O2 with TON of 15.38. The mechanism of water oxidation with the release of O2 was explored by CV method. Experimental results demonstrate that Co1 is a new kind of noble free molecule catalyst to the oxidation of water.
Cobaltous complexes catalyzing the oxidation of water are meaningful to the development of clean energy and new oxidation reaction. Anew ligand of 3-((bis(pyridin-2-ylmethyl)amino)methyl)phenyl)(3,5-dimethyl-1H-pyrrol-2-yl)methanone and the cobaltous complex (Co1) were synthesized and characterized by IR, UV, NMR, ES-MS, et al. methods. The oxidation of water catalyzed by Co1 in aqueous solution was studied. Results show that the complex Co1 can catalyze the oxidation of water to release the O2 with TON of 15.38. The mechanism of water oxidation with the release of O2 was explored by CV method. Experimental results demonstrate that Co1 is a new kind of noble free molecule catalyst to the oxidation of water.
2014, 30(4): 885-894
doi: 10.11862/CJIC.2014.155
Abstract:
BaHfO3:Ce powders were prepared by normal strike co-precipitation(NSC) method and reverse strike co-precipitation(RSC) method respectively. The phase composition, particle morphology and luminescence properties of BaHfO3:Ce powders were characterized by XRD, TG-DTA and SEM. The effect of different precipitation methods on synthesis kinetics of particle was investigated at different heating rates. The results show that the precursors prepared by NSC and RSC decompose in three stages. The apparent activation energy of each stage is calculated using the Doyle-Ozawa and Kissinger methods. The average apparent activation energies of the three reaction stages of precursors prepared by NSC and RSC are 83.41, 61.70, 262.11 kJ·mol-1 and 81.70, 42.86, 253.44 kJ·mol-1 respectively. The activation energies of grain growth for BaHfO3:Ce powders prepared by NSCand RSCare 27.36 kJ·mol-1 and 23.07 kJ·mol-1 severally. The powder prepared by RSC method exhibits excellent luminescence properties with higher intensity of excitation spectrum excited by 530nm and emission spectrum excited by 399 nm. The BaHfO3:Ce ceramic is partly transparent after being sintered at 2073 Kin vacuum for 3 h.
BaHfO3:Ce powders were prepared by normal strike co-precipitation(NSC) method and reverse strike co-precipitation(RSC) method respectively. The phase composition, particle morphology and luminescence properties of BaHfO3:Ce powders were characterized by XRD, TG-DTA and SEM. The effect of different precipitation methods on synthesis kinetics of particle was investigated at different heating rates. The results show that the precursors prepared by NSC and RSC decompose in three stages. The apparent activation energy of each stage is calculated using the Doyle-Ozawa and Kissinger methods. The average apparent activation energies of the three reaction stages of precursors prepared by NSC and RSC are 83.41, 61.70, 262.11 kJ·mol-1 and 81.70, 42.86, 253.44 kJ·mol-1 respectively. The activation energies of grain growth for BaHfO3:Ce powders prepared by NSCand RSCare 27.36 kJ·mol-1 and 23.07 kJ·mol-1 severally. The powder prepared by RSC method exhibits excellent luminescence properties with higher intensity of excitation spectrum excited by 530nm and emission spectrum excited by 399 nm. The BaHfO3:Ce ceramic is partly transparent after being sintered at 2073 Kin vacuum for 3 h.
2014, 30(4): 895-900
doi: 10.11862/CJIC.2014.132
Abstract:
The title complexes, [Cd(diaba)(phen)2] NO3·H2O(1) and [Zn(diaba)(2,2'-bipy)2](2) (diaba=3,5-diaminobenzoic acid; phen=1,10-phenanthroline, 2,2'-bipy=2,2'-bipyridine), has been synthesized by hydrothermal reactions and characterized by IR, TG, fluorescent spectrum and single-crystal X-ray diffraction techniques. The structure indicates that the complex 1 crystallizes in orthorhombic, space group Fddd with a=1.42581(7) nm, b=2.56462(13) nm, c=3.09247(17) nm. The structure indicates that the complex 2 crystallizes in monoclinic, space group C2/c with a=1.27362 nm, b=1.59278 nm, c=1.51935 nm, β=107.334°. The crystal structure of complex 1 consists of one CdⅡ, one 3,5-diaminobenzoic acid ligand and two phen ligands. The crystal structure of complex 2 consists of one ZnⅡ, one 3,5-diaminobenzoic acid ligand and two 2,2'-bipy ligands. In two complexes, the adjacent mononuclear molecular recognize each other to generate a 3Dsupramolecular structure via the hydrogen bonding or the π-π stacking interaction. In additional, thermal stability and photoluminescence properties of two complexes have also been studied.
The title complexes, [Cd(diaba)(phen)2] NO3·H2O(1) and [Zn(diaba)(2,2'-bipy)2](2) (diaba=3,5-diaminobenzoic acid; phen=1,10-phenanthroline, 2,2'-bipy=2,2'-bipyridine), has been synthesized by hydrothermal reactions and characterized by IR, TG, fluorescent spectrum and single-crystal X-ray diffraction techniques. The structure indicates that the complex 1 crystallizes in orthorhombic, space group Fddd with a=1.42581(7) nm, b=2.56462(13) nm, c=3.09247(17) nm. The structure indicates that the complex 2 crystallizes in monoclinic, space group C2/c with a=1.27362 nm, b=1.59278 nm, c=1.51935 nm, β=107.334°. The crystal structure of complex 1 consists of one CdⅡ, one 3,5-diaminobenzoic acid ligand and two phen ligands. The crystal structure of complex 2 consists of one ZnⅡ, one 3,5-diaminobenzoic acid ligand and two 2,2'-bipy ligands. In two complexes, the adjacent mononuclear molecular recognize each other to generate a 3Dsupramolecular structure via the hydrogen bonding or the π-π stacking interaction. In additional, thermal stability and photoluminescence properties of two complexes have also been studied.
2014, 30(4): 901-906
doi: 10.11862/CJIC.2014.045
Abstract:
Anew zinc(Ⅱ) coordination polymer {[Zn3(Hdmtrz)2(1,4-bdc)3]·2H2O}n (1), where Hdmtrz=3,5-dimethyl-1-H-1,2,4-triazole and 1,4-bdc=1,4-benzenedicarboxylate dianion, has been prepared by hydrothermal method and structurally characterized by elemental analysis, infrared spectra, X-ray powder diffraction, thermogravimetric analysis and single-crystal X-ray diffraction. The title compound crystallizes in triclinic, space group P1 with a=0.91797(18) nm, b=0.9833(2) nm, c=1.0717(2) nm, α=100.81(3)°, β=102.589(3)°, γ=106.90(3)°, V=0.8418(3) nm3, Z=1, and compound 1 shows a 3D framework with Schläfli symbols of {412·63} which is a typical pcu(α-Po) structure. The zinc(Ⅱ) complex exhibits strong fluorescence absorption at 471 nm (λmax) in the solid state at room temperature.
Anew zinc(Ⅱ) coordination polymer {[Zn3(Hdmtrz)2(1,4-bdc)3]·2H2O}n (1), where Hdmtrz=3,5-dimethyl-1-H-1,2,4-triazole and 1,4-bdc=1,4-benzenedicarboxylate dianion, has been prepared by hydrothermal method and structurally characterized by elemental analysis, infrared spectra, X-ray powder diffraction, thermogravimetric analysis and single-crystal X-ray diffraction. The title compound crystallizes in triclinic, space group P1 with a=0.91797(18) nm, b=0.9833(2) nm, c=1.0717(2) nm, α=100.81(3)°, β=102.589(3)°, γ=106.90(3)°, V=0.8418(3) nm3, Z=1, and compound 1 shows a 3D framework with Schläfli symbols of {412·63} which is a typical pcu(α-Po) structure. The zinc(Ⅱ) complex exhibits strong fluorescence absorption at 471 nm (λmax) in the solid state at room temperature.
2014, 30(4): 907-912
doi: 10.11862/CJIC.2014.140
Abstract:
Anew 1D lead(Ⅱ) coordination polymer, [Pb(4-cpa)2(H2O)]n (1, 4-cpa=4-chlorophenylacetate), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TGA, powder X-ray diffraction and single crystal X-ray diffraction. Structural determination reveals that 1 exhibits an interesting 1D chain structure constructed by 4-cpa ligands. Solid-state 1 emits the intensely blue photoluminescence with fluorescence lifetime of 5.3 ns (422 nm) at room temperature. The 4-Hcpa ligand and complex 1 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-p-ethyl.
Anew 1D lead(Ⅱ) coordination polymer, [Pb(4-cpa)2(H2O)]n (1, 4-cpa=4-chlorophenylacetate), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TGA, powder X-ray diffraction and single crystal X-ray diffraction. Structural determination reveals that 1 exhibits an interesting 1D chain structure constructed by 4-cpa ligands. Solid-state 1 emits the intensely blue photoluminescence with fluorescence lifetime of 5.3 ns (422 nm) at room temperature. The 4-Hcpa ligand and complex 1 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-p-ethyl.
2014, 30(4): 913-920
doi: 10.11862/CJIC.2014.092
Abstract:
Two new Co(Ⅱ) complexes, [Co(SD)2(2,2'-bpy)] (1) and {[Co(SD)2(4,4'-bpy)]·4H2O}n (2) (SD=sulfadiazine, 2,2'-bpy=2,2'-bipyridine, 4,4'-bpy=4,4'-bipyridine) have been synthesized through hydrothermal reaction and characterized by elemental analysis, IR, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and cyclic voltammetry (CV). Single crystal X-ray analysis reveals that compound 1 crystallizes in the triclinic system, space group P1 and compound 2 crystallizes in monoclinic crystal system, space group C2/c. It is found that these two compounds have electrochemical response behaviors for H2O2 and HCHO.
Two new Co(Ⅱ) complexes, [Co(SD)2(2,2'-bpy)] (1) and {[Co(SD)2(4,4'-bpy)]·4H2O}n (2) (SD=sulfadiazine, 2,2'-bpy=2,2'-bipyridine, 4,4'-bpy=4,4'-bipyridine) have been synthesized through hydrothermal reaction and characterized by elemental analysis, IR, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and cyclic voltammetry (CV). Single crystal X-ray analysis reveals that compound 1 crystallizes in the triclinic system, space group P1 and compound 2 crystallizes in monoclinic crystal system, space group C2/c. It is found that these two compounds have electrochemical response behaviors for H2O2 and HCHO.
2014, 30(4): 921-929
doi: 10.11862/CJIC.2014.145
Abstract:
Three novel polymer-bound Schiff bases and their Cr(Ⅲ) complexes were synthesized from the reaction of polystyrene-A-NH2 with 5-fluoro-2-hydroxybenzaldehyde/5-fluoro-3-chloro-2-hydroxybenzaldehyde/5-fluoro-3-methyl-2-hydroxybenzaldehyde and were characterized by elemental analysis, magnetic susceptibility, IR, 1H NMR, UV-Vis, TG/DTA analysis. The biological activities of synthesized compounds were screened against some gram-positive bacteria (Bacillus cereus sp., Listeria monocytogenes 4b, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermis) with some gram-negative bacteria (Brucella abortus, Escherichia coli, Pseudomonas putida sp., Shigella dysenteria type 10, Salmonella typhi H) and yeast (Candida albicans) by the well-diffusion method.
Three novel polymer-bound Schiff bases and their Cr(Ⅲ) complexes were synthesized from the reaction of polystyrene-A-NH2 with 5-fluoro-2-hydroxybenzaldehyde/5-fluoro-3-chloro-2-hydroxybenzaldehyde/5-fluoro-3-methyl-2-hydroxybenzaldehyde and were characterized by elemental analysis, magnetic susceptibility, IR, 1H NMR, UV-Vis, TG/DTA analysis. The biological activities of synthesized compounds were screened against some gram-positive bacteria (Bacillus cereus sp., Listeria monocytogenes 4b, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermis) with some gram-negative bacteria (Brucella abortus, Escherichia coli, Pseudomonas putida sp., Shigella dysenteria type 10, Salmonella typhi H) and yeast (Candida albicans) by the well-diffusion method.
2014, 30(4): 930-936
doi: 10.11862/CJIC.2014.145
Abstract:
Reaction of 4-(4-pyridylmethylthio)benzoic acid with (Ph3Sn)2O and Cy3SnOH (Cy=cyclohexyl) yielded triphenyltin 4-(4-pyridylmethylthio)benzoate (1) and tricyclohexyltin 4-(4-pyridylmethylthio)benzoate (2), respectively. Their crystal structures were determined by single-crystal X-ray diffraction analysis. The crystal of 1 belongs to the monoclinic system, space group P21/n with a=1.0231(5) nm, b=1.6300(8) nm, c=1.5849(8) nm, β=106.417(11)°, V=2.535(2) nm3, Z=4, Dc=1.557 g·cm-3, μ=1.120 mm-1, F(000)=1200, R1=0.0655 and wR2=0.1427. Complex 2 crystallizes with a molecule of water. Its crystal belongs to the monoclinic system, space group P21/c with a=1.0195(2) nm, b=2.1129(4) nm, c=1.4411(3) nm, β=103.847(3)°, V=3.0140(11) nm3, Z=4, Dc=1.389 g·cm-3, μ=0.948 mm-1, F(000)=1312, R1=0.0237 and wR2=0.0540. Complex 1 shows a polymeric chain structure, while complex 2 displays an infinite 2Dnetwork through intermolecular O-H…O and O-H…N hydrogen bonds. The cytotoxic activity of these two complexes for A549, Bel-7402 and Hela cells in vitro was tested.
Reaction of 4-(4-pyridylmethylthio)benzoic acid with (Ph3Sn)2O and Cy3SnOH (Cy=cyclohexyl) yielded triphenyltin 4-(4-pyridylmethylthio)benzoate (1) and tricyclohexyltin 4-(4-pyridylmethylthio)benzoate (2), respectively. Their crystal structures were determined by single-crystal X-ray diffraction analysis. The crystal of 1 belongs to the monoclinic system, space group P21/n with a=1.0231(5) nm, b=1.6300(8) nm, c=1.5849(8) nm, β=106.417(11)°, V=2.535(2) nm3, Z=4, Dc=1.557 g·cm-3, μ=1.120 mm-1, F(000)=1200, R1=0.0655 and wR2=0.1427. Complex 2 crystallizes with a molecule of water. Its crystal belongs to the monoclinic system, space group P21/c with a=1.0195(2) nm, b=2.1129(4) nm, c=1.4411(3) nm, β=103.847(3)°, V=3.0140(11) nm3, Z=4, Dc=1.389 g·cm-3, μ=0.948 mm-1, F(000)=1312, R1=0.0237 and wR2=0.0540. Complex 1 shows a polymeric chain structure, while complex 2 displays an infinite 2Dnetwork through intermolecular O-H…O and O-H…N hydrogen bonds. The cytotoxic activity of these two complexes for A549, Bel-7402 and Hela cells in vitro was tested.
2014, 30(4): 937-944
doi: 10.11862/CJIC.2014.097
Abstract:
Carbon dots (CDs) were prepared via a simple chemical oxidation route using activated carbon as the carbon precursor and a mixture of hydrogen peroxide and acetic acid as the oxidant. The obtained CDs were further purified by diethyl ether and passivated by polyethylene glycol 2000 (PEG2000). When excited at 316 nm, the maximum emission wavelength of the CDs is about 435 nm, with a quantum yield of 19.6%. Based on fluorescence quenching, a novel method for assay of oxytetracycline hydrochloride (OTC) was developed with PEG2000-passivated CDs. Alinear relationship between the change of fluorescence intensity and the concentration of OTC (1.66~49.69 μg·mL-1) was obtained with a relation coefficient of 0.9986. The recovery was in the range of 98.0% to 102.0% with a relative standard deviation of 1.7%, and the limit of detection was 1.4×10-3 μg·mL-1.
Carbon dots (CDs) were prepared via a simple chemical oxidation route using activated carbon as the carbon precursor and a mixture of hydrogen peroxide and acetic acid as the oxidant. The obtained CDs were further purified by diethyl ether and passivated by polyethylene glycol 2000 (PEG2000). When excited at 316 nm, the maximum emission wavelength of the CDs is about 435 nm, with a quantum yield of 19.6%. Based on fluorescence quenching, a novel method for assay of oxytetracycline hydrochloride (OTC) was developed with PEG2000-passivated CDs. Alinear relationship between the change of fluorescence intensity and the concentration of OTC (1.66~49.69 μg·mL-1) was obtained with a relation coefficient of 0.9986. The recovery was in the range of 98.0% to 102.0% with a relative standard deviation of 1.7%, and the limit of detection was 1.4×10-3 μg·mL-1.
2014, 30(4): 945-951
doi: 10.11862/CJIC.2014.148
Abstract:
Two compounds CoCl4(Athpp)2·2H2O (1) and CuCl4(Athpp)2 (2) were respectively obtained by the reactions of 3-amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole (Athpp) with cobalt(Ⅱ) chlorine and copper(Ⅱ) chlorine. The compounds have been characterized by FT-IR, elemental analyses and crystal structures. The compound 1 crystallizes in P1 space group and the compound 2 crystallizes in P21/n space group. The central metals are adopt distorted octahedral geometry. In addition, the fluorescent spectroscopy of the compounds were studied in solid state at room temperature.
Two compounds CoCl4(Athpp)2·2H2O (1) and CuCl4(Athpp)2 (2) were respectively obtained by the reactions of 3-amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole (Athpp) with cobalt(Ⅱ) chlorine and copper(Ⅱ) chlorine. The compounds have been characterized by FT-IR, elemental analyses and crystal structures. The compound 1 crystallizes in P1 space group and the compound 2 crystallizes in P21/n space group. The central metals are adopt distorted octahedral geometry. In addition, the fluorescent spectroscopy of the compounds were studied in solid state at room temperature.
2014, 30(4): 952-960
doi: 10.11862/CJIC.2014.121
Abstract:
The effect of additives, 2-Butyne-1,4-diol (BDO) and ethylene diamine (EDA), was investigated on the electrodeposition of Cu from 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ([HMIM]OTF). The results of UV-Vis absorption spectra and Cyclic voltammograms indicate that the reduction potential of Cu shifts to the positive side with the addition of BDO without any changes in the coordination environment of Cu2+. The adsorption of BDO on surface of working electrode results in a change in morphology of the obtained deposit. In the presence of EDA, the coordination environment of Cu2+ is changed, suggesting the formation of a new complex by Cu2+ and EDA. The deposition potential shifts to the positive side with addition of EDA. Scanning electron microscope and atomic force microscope tests show that the surface morphology of the obtained deposit is flatter and more granular compared to that without EDA. When BDO and EDA are added into [HMIM]OTF at the same time, the deposition potential still shifts positively and nano-sized grains are obtained.
The effect of additives, 2-Butyne-1,4-diol (BDO) and ethylene diamine (EDA), was investigated on the electrodeposition of Cu from 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ([HMIM]OTF). The results of UV-Vis absorption spectra and Cyclic voltammograms indicate that the reduction potential of Cu shifts to the positive side with the addition of BDO without any changes in the coordination environment of Cu2+. The adsorption of BDO on surface of working electrode results in a change in morphology of the obtained deposit. In the presence of EDA, the coordination environment of Cu2+ is changed, suggesting the formation of a new complex by Cu2+ and EDA. The deposition potential shifts to the positive side with addition of EDA. Scanning electron microscope and atomic force microscope tests show that the surface morphology of the obtained deposit is flatter and more granular compared to that without EDA. When BDO and EDA are added into [HMIM]OTF at the same time, the deposition potential still shifts positively and nano-sized grains are obtained.
2014, 30(4): 961-968
doi: 10.11862/CJIC.2014.137
Abstract:
Fe3+ doped three-dimensional Bi2WO6 hierarchical nanoarchitectures have been synthesized via a hydr-othermal process. XRD, FE-SEM, HRTEM, EDS and UV-Vis-DRS techniques were employed to characterize the phase composition, morphology and spectrum properties of the as-synthesized samples. Rhodamine Bwas selected as a model pollutant to investigate the photocatalytic activity of the as-synthesized sample under visible-light. The results indicate that Fe3+ doped Bi2WO6 exhibits a novel hierarchical nanoarchitectures, and Fe3+ doping can enhance the photocatalytic activity of Bi2WO6 photocatalyst, the amount of Fe3+ doping has a serious effect on the photocatalytic activity of Bi2WO6 photocatalyst. The results also reveal that Fe3+ doped Bi2WO6 nanoarchitecture with high stability is easy to be recycled. Furthermore, the mechanism for the enhancement of the photocatalytic activity was also investigated. The doped electron deficient Fe3+ ions could act as electron traps and facilitate the separation of photogenerated electron-hole pairs, thus improve the photocatalytic efficiency.
Fe3+ doped three-dimensional Bi2WO6 hierarchical nanoarchitectures have been synthesized via a hydr-othermal process. XRD, FE-SEM, HRTEM, EDS and UV-Vis-DRS techniques were employed to characterize the phase composition, morphology and spectrum properties of the as-synthesized samples. Rhodamine Bwas selected as a model pollutant to investigate the photocatalytic activity of the as-synthesized sample under visible-light. The results indicate that Fe3+ doped Bi2WO6 exhibits a novel hierarchical nanoarchitectures, and Fe3+ doping can enhance the photocatalytic activity of Bi2WO6 photocatalyst, the amount of Fe3+ doping has a serious effect on the photocatalytic activity of Bi2WO6 photocatalyst. The results also reveal that Fe3+ doped Bi2WO6 nanoarchitecture with high stability is easy to be recycled. Furthermore, the mechanism for the enhancement of the photocatalytic activity was also investigated. The doped electron deficient Fe3+ ions could act as electron traps and facilitate the separation of photogenerated electron-hole pairs, thus improve the photocatalytic efficiency.
