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2018 Volume 34 Issue 7
2018, 34(7): 1199-1208
doi: 10.11862/CJIC.2018.117
Abstract:
Cu(Ⅱ) and Zn(Ⅱ) ions were selected as the basic mixed metal nodes connected by organic ligand 1, 4-benzenedicarboxylic acid (BDC) and synthesized nanoporous Zn-Cu based mixed-metal MOFs Zn(BDC)-Cu, Cu(BDC)-Zn and Zn-Cu-BDC through different synthetic routes. Through characterization of PXRD, SEM, UV-Vis DRS, FT-IR, XPS and UPS and systematic analysis, it is found that the solar light absorbing range of Zn(BDC) is located in UV band (< 400 nm), while Cu(BDC) mainly absorbs the whole visible light (500~1 000 nm). Additionally, the Zn-Cu ions uniformly-dispersed product Zn-Cu-BDC performs better in light-absorption and exhibits lower photo band-gap and HOMO level than the other bi-metallic products Zn(BDC)-Cu and Cu(BDC)-Zn. The investigation might inspire the design of heterogeneous photocatalysts and organic-inorganic hybrids in the aspects of light-absorption and charge transfer and construction methods on metal exchange due to different routes leading to different properties despite of the same components.
Cu(Ⅱ) and Zn(Ⅱ) ions were selected as the basic mixed metal nodes connected by organic ligand 1, 4-benzenedicarboxylic acid (BDC) and synthesized nanoporous Zn-Cu based mixed-metal MOFs Zn(BDC)-Cu, Cu(BDC)-Zn and Zn-Cu-BDC through different synthetic routes. Through characterization of PXRD, SEM, UV-Vis DRS, FT-IR, XPS and UPS and systematic analysis, it is found that the solar light absorbing range of Zn(BDC) is located in UV band (< 400 nm), while Cu(BDC) mainly absorbs the whole visible light (500~1 000 nm). Additionally, the Zn-Cu ions uniformly-dispersed product Zn-Cu-BDC performs better in light-absorption and exhibits lower photo band-gap and HOMO level than the other bi-metallic products Zn(BDC)-Cu and Cu(BDC)-Zn. The investigation might inspire the design of heterogeneous photocatalysts and organic-inorganic hybrids in the aspects of light-absorption and charge transfer and construction methods on metal exchange due to different routes leading to different properties despite of the same components.
2018, 34(7): 1209-1220
doi: 10.11862/CJIC.2018.167
Abstract:
Carbon nanotube-supported Pd-based binary and ternary nanocatalysts (Pd/CNT, Pd7Ag3/CNT, Pd7Sn2/CNT, Pd7Ag1Sn2/CNT, Pd7Ag2Sn2/CNT and Pd7Ag3Sn2/CNT) have been fabricated by the NaBH4 reduction method. They have been characterized by using XRD, TEM and XPS techniques. The ternary Pd-Ag-Sn nanoparticles exhibit a smaller average particle size of ca. 2.3 nm compared to Pd/CNT and binary Pd-Ag (or Pd-Sn) nanoparticles. The electrocatalytic activity of these catalysts towards formic acid oxidation in both H2SO4 and NaOH solutions has been investigated using cyclic voltammetry (CV) and chronoamperometry (CA). In both acidic and alkaline media, the ternary Pd-Ag-Sn/CNT catalysts present higher anodic current density for formic acid oxidation than Pd/CNT and binary PdAg/CNT or PdSn/CNT catalysts. Among the prepared catalysts, the Pd7Ag2Sn2/CNT catalyst displays the highest HCOOH oxidation current density of 108.8 mA·cm-2 in 0.5 mol·L-1 H2SO4 solution or 211.3 mA·cm-2 in 1 mol·L-1 NaOH solution, corresponding to the Pd mass current density of 1 364 or 2 640 mA·mg-1, respectively. These currents are extremely larger than those obtained from the commercial Pd/C. Results exhibit the excellent electrocatalytic activity of the ternary Pd7Ag2Sn2/CNT catalyst towards formic acid oxidation.
Carbon nanotube-supported Pd-based binary and ternary nanocatalysts (Pd/CNT, Pd7Ag3/CNT, Pd7Sn2/CNT, Pd7Ag1Sn2/CNT, Pd7Ag2Sn2/CNT and Pd7Ag3Sn2/CNT) have been fabricated by the NaBH4 reduction method. They have been characterized by using XRD, TEM and XPS techniques. The ternary Pd-Ag-Sn nanoparticles exhibit a smaller average particle size of ca. 2.3 nm compared to Pd/CNT and binary Pd-Ag (or Pd-Sn) nanoparticles. The electrocatalytic activity of these catalysts towards formic acid oxidation in both H2SO4 and NaOH solutions has been investigated using cyclic voltammetry (CV) and chronoamperometry (CA). In both acidic and alkaline media, the ternary Pd-Ag-Sn/CNT catalysts present higher anodic current density for formic acid oxidation than Pd/CNT and binary PdAg/CNT or PdSn/CNT catalysts. Among the prepared catalysts, the Pd7Ag2Sn2/CNT catalyst displays the highest HCOOH oxidation current density of 108.8 mA·cm-2 in 0.5 mol·L-1 H2SO4 solution or 211.3 mA·cm-2 in 1 mol·L-1 NaOH solution, corresponding to the Pd mass current density of 1 364 or 2 640 mA·mg-1, respectively. These currents are extremely larger than those obtained from the commercial Pd/C. Results exhibit the excellent electrocatalytic activity of the ternary Pd7Ag2Sn2/CNT catalyst towards formic acid oxidation.
2018, 34(7): 1221-1230
doi: 10.11862/CJIC.2018.139
Abstract:
A coordination polymer of {[Mn(Qina)2(Bpp)]·2/3H2O}n (Qina=2-quinolinecarboxylic-carboxylate, Bpp=4, 4'-trimethylenedipyridine) was synthesized and successfully obtained as single crystals. In the crystal, each Mn(Ⅱ) ion is chelated by two Qina groups, with each Bpp ligand bridging two Mn(Ⅱ) ions to form the 1D polymer chains. Furthermore, the 3D supramolecular architecture is directed by 1D-interchains via weak stacking interactions of C-H…π and π…π. The competition capacity of the complex about calf thymus DNA (ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complex to cleave the plasmid DNA (pBR322-DNA) was determined by gel electrophoresis assay. And the cytotoxic activity of complex was reviewed for two kinds of cancer cell lines (Hela, MCF-7), which results show that the coordination polymer has in vitro anti-tumor activity and cytotoxicity.
A coordination polymer of {[Mn(Qina)2(Bpp)]·2/3H2O}n (Qina=2-quinolinecarboxylic-carboxylate, Bpp=4, 4'-trimethylenedipyridine) was synthesized and successfully obtained as single crystals. In the crystal, each Mn(Ⅱ) ion is chelated by two Qina groups, with each Bpp ligand bridging two Mn(Ⅱ) ions to form the 1D polymer chains. Furthermore, the 3D supramolecular architecture is directed by 1D-interchains via weak stacking interactions of C-H…π and π…π. The competition capacity of the complex about calf thymus DNA (ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complex to cleave the plasmid DNA (pBR322-DNA) was determined by gel electrophoresis assay. And the cytotoxic activity of complex was reviewed for two kinds of cancer cell lines (Hela, MCF-7), which results show that the coordination polymer has in vitro anti-tumor activity and cytotoxicity.
2018, 34(7): 1341-1350
doi: 10.11862/CJIC.2018.152
Abstract:
The transparent TeO2-WO3-La2O3-Er2O3-Yb2O3 glass-ceramics containing silver nanocrystals and micro-crystals such as Er2WO6, La2WO6 were prepared by the conventional melt-quenching method, which exhibit excellent up-conversion luminescence properties. The results show that the precipitation of silver nanocrystals and micro-crystals was related to the introducing way of silver nanocrystals and heat treatment temperature. After heat treated at 390℃ for 15 min, the luminescent intensity of the glass co-doped with AgCl and AgNO3 is higher than the glass which is single doped with AgCl or AgNO3. The introduction of silver nanocrystals and microcrystals can synergistically increase the UC luminescence of the tellurite glass.
The transparent TeO2-WO3-La2O3-Er2O3-Yb2O3 glass-ceramics containing silver nanocrystals and micro-crystals such as Er2WO6, La2WO6 were prepared by the conventional melt-quenching method, which exhibit excellent up-conversion luminescence properties. The results show that the precipitation of silver nanocrystals and micro-crystals was related to the introducing way of silver nanocrystals and heat treatment temperature. After heat treated at 390℃ for 15 min, the luminescent intensity of the glass co-doped with AgCl and AgNO3 is higher than the glass which is single doped with AgCl or AgNO3. The introduction of silver nanocrystals and microcrystals can synergistically increase the UC luminescence of the tellurite glass.
2018, 34(7): 1351-1364
doi: 10.11862/CJIC.2018.156
Abstract:
The influences of seed crystals and crystallization temperatures on the formation evolution and performance of zeolite T membranes were investigated, revealing that dense membranes could be obtained by using smaller seeds and the membrane growth rate was significantly affected by crystallization temperature. High performance zeolite T membranes with flux of 6.21 and 5.98 kg·m-2·h-1 respectively and high separation factor (> 10 000) for 90%(w/w) isopropanol solution at 348 K were obtained by using 0.4 and 0.6 μm seeds at 423 K for 4 h. A much long synthesis time was required at low temperature for achieving similar separation performance. It was found that the membrane formation was governed by the same mechanism of epitaxial growth, independent on the seed size and morphology and the crystallization temperature for the investigated synthesis solution. Furthermore, the zeolite T membranes show good hydrothermal and acid stability.
The influences of seed crystals and crystallization temperatures on the formation evolution and performance of zeolite T membranes were investigated, revealing that dense membranes could be obtained by using smaller seeds and the membrane growth rate was significantly affected by crystallization temperature. High performance zeolite T membranes with flux of 6.21 and 5.98 kg·m-2·h-1 respectively and high separation factor (> 10 000) for 90%(w/w) isopropanol solution at 348 K were obtained by using 0.4 and 0.6 μm seeds at 423 K for 4 h. A much long synthesis time was required at low temperature for achieving similar separation performance. It was found that the membrane formation was governed by the same mechanism of epitaxial growth, independent on the seed size and morphology and the crystallization temperature for the investigated synthesis solution. Furthermore, the zeolite T membranes show good hydrothermal and acid stability.
2018, 34(7): 1365-1372
doi: 10.11862/CJIC.2018.163
Abstract:
Two coordination polymers {[Ni(bbmb)(dcpe)(H2O)]·2H2O}n (1) and {[Mn2(bbmb)(dcpe)2(H2O)]·1.5H2O}n (2) have been synthesized utilizing a linear benzimidazole ligand 4, 4'-bis(benzimidazol-1-ylmethy1)biphenyl) (bbmb) combined with a V-shaped dicarboxylates ligand 4, 4'-dicarboxydiphenyl ether (H2dcpe). Compound 1 possesses a 2D thick layer structure with sql topology. Compound 2 possesses a 2D thick layer network with a linear tetranuclear Mn4 cluster within the network. The in vitro antimicrobial activities showed that both compounds have effective inhibiting effects.
Two coordination polymers {[Ni(bbmb)(dcpe)(H2O)]·2H2O}n (1) and {[Mn2(bbmb)(dcpe)2(H2O)]·1.5H2O}n (2) have been synthesized utilizing a linear benzimidazole ligand 4, 4'-bis(benzimidazol-1-ylmethy1)biphenyl) (bbmb) combined with a V-shaped dicarboxylates ligand 4, 4'-dicarboxydiphenyl ether (H2dcpe). Compound 1 possesses a 2D thick layer structure with sql topology. Compound 2 possesses a 2D thick layer network with a linear tetranuclear Mn4 cluster within the network. The in vitro antimicrobial activities showed that both compounds have effective inhibiting effects.
2018, 34(7): 1373-1380
doi: 10.11862/CJIC.2018.182
Abstract:
FeWO4 microcrystals were fabricated through a simple solution-based route. Then, FeWO4 samples were annealed under the circumstance of air, with the temperature of 310℃, and the annealing process is firstly studied for its influence on FeWO4 microcrystals. The FeWO4 microcrystals, before and after annealing treatment, were characterized by XRD, SEM, TEM, N2 adsorption-desorption, TG, IR, and UV-Vis analysis. Annealed FeWO4 samples show highly active in degradation of rhodamine B (RhB). It reveals that the adsorptive and photocatalytic properties of FeWO4 microcrystals are probably enhanced through annealing treatment.
FeWO4 microcrystals were fabricated through a simple solution-based route. Then, FeWO4 samples were annealed under the circumstance of air, with the temperature of 310℃, and the annealing process is firstly studied for its influence on FeWO4 microcrystals. The FeWO4 microcrystals, before and after annealing treatment, were characterized by XRD, SEM, TEM, N2 adsorption-desorption, TG, IR, and UV-Vis analysis. Annealed FeWO4 samples show highly active in degradation of rhodamine B (RhB). It reveals that the adsorptive and photocatalytic properties of FeWO4 microcrystals are probably enhanced through annealing treatment.
2018, 34(7): 1381-1391
doi: 10.11862/CJIC.2018.151
Abstract:
Two newly designed complexes, [Cu(L1)(H2O)] (1) and [Co3(L2)2(μ2-OAc)2(MeOH)2]·3CH2Cl2 (2) derived from tetradentate Salamo-type chelating ligands (H2L1 and H2L2) have been synthesized and characterized by elemental analyses, IR and UV-Vis spectra, fluorescence spectra and X-ray crystallography. Complex 1 shows a slightly distorted tetragonal pyramid, forming a dimer supramolecular structure by intermolecular hydrogen bond interactions. While all of the Co(Ⅱ) ions in complex 2 are hexa-coordinated with slightly distorted octahedral coordination geometries. The supramolecular structure of complex 2 is formed via intermolecular hydrogen bond interactions leading to a self-assembly infinite 1D chain structure. The fluorescent properties of H2L1 and H2L2 have been discussed and the crystal structures of complexes 1 and 2 were confirmed by fluorescence titration experiments.
Two newly designed complexes, [Cu(L1)(H2O)] (1) and [Co3(L2)2(μ2-OAc)2(MeOH)2]·3CH2Cl2 (2) derived from tetradentate Salamo-type chelating ligands (H2L1 and H2L2) have been synthesized and characterized by elemental analyses, IR and UV-Vis spectra, fluorescence spectra and X-ray crystallography. Complex 1 shows a slightly distorted tetragonal pyramid, forming a dimer supramolecular structure by intermolecular hydrogen bond interactions. While all of the Co(Ⅱ) ions in complex 2 are hexa-coordinated with slightly distorted octahedral coordination geometries. The supramolecular structure of complex 2 is formed via intermolecular hydrogen bond interactions leading to a self-assembly infinite 1D chain structure. The fluorescent properties of H2L1 and H2L2 have been discussed and the crystal structures of complexes 1 and 2 were confirmed by fluorescence titration experiments.
2018, 34(7): 1392-1398
doi: 10.11862/CJIC.2018.185
Abstract:
TiN nanotube arrays (NTAs) was prepared by calcining the anodized TiO2 NTAs in NH3 atmosphere at elevated temperatures, which were used as surface-enhanced Raman scattering (SERS) substrates. The composition, morphology and optical property of the TiN NTAs were characterized by XRD, SEM, UV-Vis and XPS. SERS activity of the TiN NTAs substrates was evaluated using rhodamine 6G (R6G) as probe molecules. The results showed that TiN NTAs were obtained at nitridation temperatures above 800℃, and the nanotubes exhibit ordered tubular structure with pore diameters of 100~200 nm. The UV-Vis spectra exhibited plasmon resonance peaks of TiN NTAs in the wavelength range of 500~600 nm. The TiN NTAs substrates provided superior SERS sensitivity towards R6G, with a detection limit of ~10-7 mol·L-1 and the enhancement factor of ~105.
TiN nanotube arrays (NTAs) was prepared by calcining the anodized TiO2 NTAs in NH3 atmosphere at elevated temperatures, which were used as surface-enhanced Raman scattering (SERS) substrates. The composition, morphology and optical property of the TiN NTAs were characterized by XRD, SEM, UV-Vis and XPS. SERS activity of the TiN NTAs substrates was evaluated using rhodamine 6G (R6G) as probe molecules. The results showed that TiN NTAs were obtained at nitridation temperatures above 800℃, and the nanotubes exhibit ordered tubular structure with pore diameters of 100~200 nm. The UV-Vis spectra exhibited plasmon resonance peaks of TiN NTAs in the wavelength range of 500~600 nm. The TiN NTAs substrates provided superior SERS sensitivity towards R6G, with a detection limit of ~10-7 mol·L-1 and the enhancement factor of ~105.
2018, 34(7): 1231-1239
doi: 10.11862/CJIC.2018.165
Abstract:
The controllable preparation of three-dimensional ordered gold nano-shells (GNSs) structure was carried out by SiO2 colloidal crystal as template and H2O2 as reducing agent in situ growth of gold seed, and then surface enhanced Raman spectroscopy (SERS) properties were studied in the growth process. The experimental results show that the controllable batch preparation of three-dimensional ordered GNSs array can be achieved by controlling the reaction time, reaction temperature, reducing agent H2O2 and the quantity of growth liquid K2CO3-HAuCl4, and the hollow ordered GNSs structure is obtained by removing the SiO2 core. Through the study of its SERS properties, it is found that the SiO2 surface is completely covered by Au with rough structure showing the best SERS performance, and the corresponding hollow ordered GNSs structure shows superior SERS activity.
The controllable preparation of three-dimensional ordered gold nano-shells (GNSs) structure was carried out by SiO2 colloidal crystal as template and H2O2 as reducing agent in situ growth of gold seed, and then surface enhanced Raman spectroscopy (SERS) properties were studied in the growth process. The experimental results show that the controllable batch preparation of three-dimensional ordered GNSs array can be achieved by controlling the reaction time, reaction temperature, reducing agent H2O2 and the quantity of growth liquid K2CO3-HAuCl4, and the hollow ordered GNSs structure is obtained by removing the SiO2 core. Through the study of its SERS properties, it is found that the SiO2 surface is completely covered by Au with rough structure showing the best SERS performance, and the corresponding hollow ordered GNSs structure shows superior SERS activity.
2018, 34(7): 1240-1248
doi: 10.11862/CJIC.2018.154
Abstract:
Histidine-functionalized carbon dots(His-CDs) were used as a stabilizer for hydrothermal synthesis of His-CDs@NaTbF4. The formed NaTbF4 is a hexagonal crystal, its surface is covalently coated by carbon dots, and the crystal size is only in the range of 4~6 nm. The small size and rich of hydrophilic groups make the composite easy to disperse in water. The resulted dispersion is of excellent stability. As the absorption spectra of His-CDs and the fluorescence emission spectrum of NaTbF4 exist a great overlap as well a short distance between His-CDs and NaTbF4, their combination brings a remarkable fluorescence resonance energy transfer. The increase in the fluorescence intensity of the His-CDs@NaTbF4 is more than 7 times that of sole carbon dots. The coordination of Cu2+ with carbon dots on NaTbF4 surface results in an obvious fluorescence quenching process. However, the quenched fluorescence can be well recovered by adding histidine. Based on the above behaviors, one "On-Off" type fluorescence scheme was established for the detection of histidine. When the histidine concentration is in the range of 1.0×10-6~2.0×10-4 mol·L-1, the peak fluorescence intensity linearly increases with the increase of histidine. The analytical method gives a detection limit of 3.8×10-7 mol·L-1, and it has been successfully applied in determination of histidine in human urine and Hela cell imaging.
Histidine-functionalized carbon dots(His-CDs) were used as a stabilizer for hydrothermal synthesis of His-CDs@NaTbF4. The formed NaTbF4 is a hexagonal crystal, its surface is covalently coated by carbon dots, and the crystal size is only in the range of 4~6 nm. The small size and rich of hydrophilic groups make the composite easy to disperse in water. The resulted dispersion is of excellent stability. As the absorption spectra of His-CDs and the fluorescence emission spectrum of NaTbF4 exist a great overlap as well a short distance between His-CDs and NaTbF4, their combination brings a remarkable fluorescence resonance energy transfer. The increase in the fluorescence intensity of the His-CDs@NaTbF4 is more than 7 times that of sole carbon dots. The coordination of Cu2+ with carbon dots on NaTbF4 surface results in an obvious fluorescence quenching process. However, the quenched fluorescence can be well recovered by adding histidine. Based on the above behaviors, one "On-Off" type fluorescence scheme was established for the detection of histidine. When the histidine concentration is in the range of 1.0×10-6~2.0×10-4 mol·L-1, the peak fluorescence intensity linearly increases with the increase of histidine. The analytical method gives a detection limit of 3.8×10-7 mol·L-1, and it has been successfully applied in determination of histidine in human urine and Hela cell imaging.
2018, 34(7): 1261-1270
doi: 10.11862/CJIC.2018.178
Abstract:
Porous carbonyl iron powder(CIP) was obtained by means of point erosion and then porous carbonyl iron/SiO2/polypyrrole(porous-CIP/SiO2/PPy) composites were prepared by the Stöber process together with the in-situ polymerization. The phase structure and micro morphology of the composites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscope(TEM), and Fourier transform infrared spectra(FT-IR). The electromagnetic parameters and microwave absorption properties were measured in 2.0~18.0 GHz by the coaxial method using network analyzer. The effect of the mass ratio of CIP/PPy on electromagnetic properties of the composites was investigated. The measured SEM and TEM show that the porous-CIP particles are firstly coated with SiO2 shell and then graft PPy to form core-shell structures. The absorption loss peak moves to lower frequency with increasing added amount of pyrrole. A minimum reflection loss (RL) of -23 dB and an effective bandwidth(RL below -10 dB) of 8.12 GHz in 9.44~17.56 GHz are obtained for coating thickness of 3.5 mm and 6%(w/w) pyrrole, which can be attributed to the effective impedance match and multiple interfacial polarizations. Owing to the low density and high absorption, the porous-CIP/SiO2/PPy composite can be a promising candidate as lightweight, efficient microwave absorbents.
Porous carbonyl iron powder(CIP) was obtained by means of point erosion and then porous carbonyl iron/SiO2/polypyrrole(porous-CIP/SiO2/PPy) composites were prepared by the Stöber process together with the in-situ polymerization. The phase structure and micro morphology of the composites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscope(TEM), and Fourier transform infrared spectra(FT-IR). The electromagnetic parameters and microwave absorption properties were measured in 2.0~18.0 GHz by the coaxial method using network analyzer. The effect of the mass ratio of CIP/PPy on electromagnetic properties of the composites was investigated. The measured SEM and TEM show that the porous-CIP particles are firstly coated with SiO2 shell and then graft PPy to form core-shell structures. The absorption loss peak moves to lower frequency with increasing added amount of pyrrole. A minimum reflection loss (RL) of -23 dB and an effective bandwidth(RL below -10 dB) of 8.12 GHz in 9.44~17.56 GHz are obtained for coating thickness of 3.5 mm and 6%(w/w) pyrrole, which can be attributed to the effective impedance match and multiple interfacial polarizations. Owing to the low density and high absorption, the porous-CIP/SiO2/PPy composite can be a promising candidate as lightweight, efficient microwave absorbents.
2018, 34(7): 1271-1278
doi: 10.11862/CJIC.2018.138
Abstract:
n-Type Cu2O films were prepared by a simplified hydro-thermal method, using only Cu plate and NaCl solution as precursors. Subsequently, the prepared samples were characterized by X-ray diffraction (XRD), laser raman spectrometer (Raman), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and photoelectrochemical methods. The technology for the preparation of n-type Cu2O films is simpler and lower cost than others and available for the industrialization. The prepared n-type Cu2O films are highly crystallized and have high carrier concentrations (up to 9.75×1017 cm-3) with Cl- doping. The photoelectrochemical and EIS measurements demonstrate that the sample prepared in 0.1 mol·L-1 NaCl solution with 50 h reaction time at 90℃ obtains the best photoelectrochemical properties.
n-Type Cu2O films were prepared by a simplified hydro-thermal method, using only Cu plate and NaCl solution as precursors. Subsequently, the prepared samples were characterized by X-ray diffraction (XRD), laser raman spectrometer (Raman), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and photoelectrochemical methods. The technology for the preparation of n-type Cu2O films is simpler and lower cost than others and available for the industrialization. The prepared n-type Cu2O films are highly crystallized and have high carrier concentrations (up to 9.75×1017 cm-3) with Cl- doping. The photoelectrochemical and EIS measurements demonstrate that the sample prepared in 0.1 mol·L-1 NaCl solution with 50 h reaction time at 90℃ obtains the best photoelectrochemical properties.
2018, 34(7): 1279-1284
doi: 10.11862/CJIC.2018.155
Abstract:
A new aqueous full battery based on LiMn2O4 cathode and NaTi2(PO4)3 anode with the hybrid ion electrolytes (1 mol·L-1 Li2SO4+0.5 mol·L-1 Na2SO4) was presented. The electrochemical performances of LiMn2O4 and NaTi2(PO4)3 in the different aqueous electrolytes (1 mol·L-1 Li2SO4, 0.5 mol·L-1 Na2SO4 and 1 mol·L-1 Li2SO4+0.5 mol·L-1 Na2SO4) were characterized by the cyclic voltammetry (1 mV·s-1) and the galvanostatic charge/discharge (265 mA·g-1). The results show that Li+ ion could de-intercalation/intercalation from/into LiMn2O4 but Na+ could not because of its larger radius, and both ions (Li+ and Na+) could intercalation/de-intercalation into/from NaTi2(PO4)3. The charge and discharge specific capacity was 100.1 and 74.9 mAh·g-1, respectively, with a higher discharge voltage (1.55 V) for this aqueous full battery.
A new aqueous full battery based on LiMn2O4 cathode and NaTi2(PO4)3 anode with the hybrid ion electrolytes (1 mol·L-1 Li2SO4+0.5 mol·L-1 Na2SO4) was presented. The electrochemical performances of LiMn2O4 and NaTi2(PO4)3 in the different aqueous electrolytes (1 mol·L-1 Li2SO4, 0.5 mol·L-1 Na2SO4 and 1 mol·L-1 Li2SO4+0.5 mol·L-1 Na2SO4) were characterized by the cyclic voltammetry (1 mV·s-1) and the galvanostatic charge/discharge (265 mA·g-1). The results show that Li+ ion could de-intercalation/intercalation from/into LiMn2O4 but Na+ could not because of its larger radius, and both ions (Li+ and Na+) could intercalation/de-intercalation into/from NaTi2(PO4)3. The charge and discharge specific capacity was 100.1 and 74.9 mAh·g-1, respectively, with a higher discharge voltage (1.55 V) for this aqueous full battery.
2018, 34(7): 1285-1292
doi: 10.11862/CJIC.2018.153
Abstract:
Two lanthanide complexes, [Gd(3, 4'-dpdc)2(HDPP)]n (1) and {[Dy(3, 4'-Hdpdc)3(H2O)]·0.5BTB}n (2) (3, 4'-H2dpdc=3, 4'-biphenyldicarboxylic acid, DPP=1, 3-bis(4-pyridyl)propane, BTB=1, 4-bis(1, 2, 4-triazol-1-yl)butane) were successfully synthesized under hydrothermal reactions, and their structures were characterized by single crystal X-ray diffraction. Complex 1 belongs to monoclinic system, space group P21/c. It is two-dimensional layered structure and consists of[GdO7N] unit. 3, 4'-dpdc ligands are connected to the Gd(Ⅲ) ions by μ1:η1η1/μ2:η1η1 and μ1:η1η1/μ1:η1η0 coordination modes. DPP ligands are end-coordinated to Gd(Ⅲ) ions. Complex 2 is a triclinic system, space group P1. The complex shows a one-dimensional chain structure. The coordination environment of Dy(Ⅲ) ion is[DyO7]. The 3, 4'-Hdpdc ligands link Dy(Ⅲ) ions in a μ2:η1η1 coordination mode. The BTB molecules are connected to the one-dimensional chains by hydrogen bonds and thus form a three-dimensional supramolecular structure. Solid state photoluminescence measurements show that compounds 1 and 2 display broad band in the range of 350~650 nm due to the π*→π transition of the ligands. The effect of different floxacins on the luminescence of complex 1 in aqueous solution was studied. The results showed that the complex could identify pefloxacin.
Two lanthanide complexes, [Gd(3, 4'-dpdc)2(HDPP)]n (1) and {[Dy(3, 4'-Hdpdc)3(H2O)]·0.5BTB}n (2) (3, 4'-H2dpdc=3, 4'-biphenyldicarboxylic acid, DPP=1, 3-bis(4-pyridyl)propane, BTB=1, 4-bis(1, 2, 4-triazol-1-yl)butane) were successfully synthesized under hydrothermal reactions, and their structures were characterized by single crystal X-ray diffraction. Complex 1 belongs to monoclinic system, space group P21/c. It is two-dimensional layered structure and consists of[GdO7N] unit. 3, 4'-dpdc ligands are connected to the Gd(Ⅲ) ions by μ1:η1η1/μ2:η1η1 and μ1:η1η1/μ1:η1η0 coordination modes. DPP ligands are end-coordinated to Gd(Ⅲ) ions. Complex 2 is a triclinic system, space group P1. The complex shows a one-dimensional chain structure. The coordination environment of Dy(Ⅲ) ion is[DyO7]. The 3, 4'-Hdpdc ligands link Dy(Ⅲ) ions in a μ2:η1η1 coordination mode. The BTB molecules are connected to the one-dimensional chains by hydrogen bonds and thus form a three-dimensional supramolecular structure. Solid state photoluminescence measurements show that compounds 1 and 2 display broad band in the range of 350~650 nm due to the π*→π transition of the ligands. The effect of different floxacins on the luminescence of complex 1 in aqueous solution was studied. The results showed that the complex could identify pefloxacin.
2018, 34(7): 1293-1302
doi: 10.11862/CJIC.2018.161
Abstract:
A one-pot co-condensation method was used to prepare three kinds of silane coupling agents containing different amounts of N atom modified and SiO2 coated magnetic adsorbents Fe3O4@SiO2-xN (x=1, 2, 3). Here, 1N, 2N, and 3N represent 3-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane and 2-[2-(3-Trimethoxysilylpropylamino)ethylamino]ethylamine, respectively. Their physicochemical properties were comparatively characterized by XRD, SEM, N2 adsorption-desorption, elemental analysis, FT-IR and ζ potential. The results showed that the modified composites present good spherical morphologies and higher isoelectric points, and their nitrogen contents show the trend of Fe3O4@SiO2-1N < Fe3O4@SiO2-2N < Fe3O4@SiO2-3N. The static adsorption experiments towards Cr(Ⅵ) showed that the corresponding maximum adsorption capacity decreases with increasing nitrogen content, namely Fe3O4@SiO2-1N (79.74 mg·g-1) > Fe3O4@SiO2-2N (63.05 mg·g-1) > Fe3O4@SiO2-3N (55.37 mg ·g-1), and the mechanism on this trend was also analyzed. The adsorption experiments on simulated wastewater showed that the Fe3O4@SiO2-1N can adsorb some kinds of heavy metal ions simultaneously, and can achieve magnetic separation within 30 s.
A one-pot co-condensation method was used to prepare three kinds of silane coupling agents containing different amounts of N atom modified and SiO2 coated magnetic adsorbents Fe3O4@SiO2-xN (x=1, 2, 3). Here, 1N, 2N, and 3N represent 3-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane and 2-[2-(3-Trimethoxysilylpropylamino)ethylamino]ethylamine, respectively. Their physicochemical properties were comparatively characterized by XRD, SEM, N2 adsorption-desorption, elemental analysis, FT-IR and ζ potential. The results showed that the modified composites present good spherical morphologies and higher isoelectric points, and their nitrogen contents show the trend of Fe3O4@SiO2-1N < Fe3O4@SiO2-2N < Fe3O4@SiO2-3N. The static adsorption experiments towards Cr(Ⅵ) showed that the corresponding maximum adsorption capacity decreases with increasing nitrogen content, namely Fe3O4@SiO2-1N (79.74 mg·g-1) > Fe3O4@SiO2-2N (63.05 mg·g-1) > Fe3O4@SiO2-3N (55.37 mg ·g-1), and the mechanism on this trend was also analyzed. The adsorption experiments on simulated wastewater showed that the Fe3O4@SiO2-1N can adsorb some kinds of heavy metal ions simultaneously, and can achieve magnetic separation within 30 s.
2018, 34(7): 1303-1311
doi: 10.11862/CJIC.2018.158
Abstract:
Microsphere high-nickel ternary LiNi0.8Mn0.1Co0.1O2 (LNCM811) cathode was syntheisized by the chemical co-precipitation method with a simple solid-state reaction, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Electrochemical behavior of LNCM811 was investigated by electrochemical impedance spectroscopy (EIS), combining with cyclic voltammogram (CV) and charge/discharge test in the 1 mol·L-1 LiPF6EC:EMC electrolyte with 2% (w/w) ethylene sulfate (DTD) and 1% (w/w) methylene methanedisulfonate (MMDS) additives either singly or in combination at room temperature of 25℃ or elevated temperature of 60℃. It is found that compared with 1% MMDS, the 2% DTD can slightly improve the initial coulombic efficiency and initial discharge capacity of the LNCM811 at room temperature. Both 2% DTD and 1% MMDS can improve the long cycling performance of LNCM811, and the 2% DTD additive is better than the 1% MMDS additive at 25℃, however, the 1% MMDS is better than the 2% DTD at elevated temperature of 60℃. After long cycles, the LNCM811 cathode has the best cycling performance with additive combination 2% DTD+1% MMDS. EIS results reveal that the additive blend of 2% DTD+1% MMDS can drastically lower the kinetics impedances.
Microsphere high-nickel ternary LiNi0.8Mn0.1Co0.1O2 (LNCM811) cathode was syntheisized by the chemical co-precipitation method with a simple solid-state reaction, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Electrochemical behavior of LNCM811 was investigated by electrochemical impedance spectroscopy (EIS), combining with cyclic voltammogram (CV) and charge/discharge test in the 1 mol·L-1 LiPF6EC:EMC electrolyte with 2% (w/w) ethylene sulfate (DTD) and 1% (w/w) methylene methanedisulfonate (MMDS) additives either singly or in combination at room temperature of 25℃ or elevated temperature of 60℃. It is found that compared with 1% MMDS, the 2% DTD can slightly improve the initial coulombic efficiency and initial discharge capacity of the LNCM811 at room temperature. Both 2% DTD and 1% MMDS can improve the long cycling performance of LNCM811, and the 2% DTD additive is better than the 1% MMDS additive at 25℃, however, the 1% MMDS is better than the 2% DTD at elevated temperature of 60℃. After long cycles, the LNCM811 cathode has the best cycling performance with additive combination 2% DTD+1% MMDS. EIS results reveal that the additive blend of 2% DTD+1% MMDS can drastically lower the kinetics impedances.
2018, 34(7): 1312-1318
doi: 10.11862/CJIC.2018.157
Abstract:
Three metal-organic coordination polymers, namely[{Zn(mal)(2, 2'-bipy)]2·5H2O}n (1), {[Zn(mal)(Phen)(H2O)]2·3H2O}n (2) and {[Cu(mal)(Phen)]2·4H2O}n (3) (H2mal=L-malic acid, 2, 2'-bipy=2, 2'-bipyridine, Phen=phenanthroline), have been synthesized by the reaction of Zn(CH3CO2)2·2H2O or CuCl2 with L-malic acid and cooperative ligand (2, 2'-bipy, Phen) in solution, respectively. They were characterized by powder and single X-ray diffraction analysis, FTIR spectroscopy and elemental analysis. Single crystal X-ray analysis reveals that complexes 1, and 2 crystallize in orthorhombic system with space group P212121. In complexes 1 and 2, the two adjacent metal atoms are bridged by one malate group, constructing a one-dimensional zigzag chain, and two parallel 1D chains are constituted to form a novel ladder double chain structure through π-π weak interaction between the pyridine or phenanthroline rings. However, complex 3 crystallizes in monoclinic system with space group P21 and copper centers are also bridged by malate group, which is linked into one dimensional chain and self-assembled to form two dimensional lamellar supramolecular architectures through weak π-π interaction between the phenanthroline rings.
Three metal-organic coordination polymers, namely[{Zn(mal)(2, 2'-bipy)]2·5H2O}n (1), {[Zn(mal)(Phen)(H2O)]2·3H2O}n (2) and {[Cu(mal)(Phen)]2·4H2O}n (3) (H2mal=L-malic acid, 2, 2'-bipy=2, 2'-bipyridine, Phen=phenanthroline), have been synthesized by the reaction of Zn(CH3CO2)2·2H2O or CuCl2 with L-malic acid and cooperative ligand (2, 2'-bipy, Phen) in solution, respectively. They were characterized by powder and single X-ray diffraction analysis, FTIR spectroscopy and elemental analysis. Single crystal X-ray analysis reveals that complexes 1, and 2 crystallize in orthorhombic system with space group P212121. In complexes 1 and 2, the two adjacent metal atoms are bridged by one malate group, constructing a one-dimensional zigzag chain, and two parallel 1D chains are constituted to form a novel ladder double chain structure through π-π weak interaction between the pyridine or phenanthroline rings. However, complex 3 crystallizes in monoclinic system with space group P21 and copper centers are also bridged by malate group, which is linked into one dimensional chain and self-assembled to form two dimensional lamellar supramolecular architectures through weak π-π interaction between the phenanthroline rings.
2018, 34(7): 1319-1326
doi: 10.11862/CJIC.2018.160
Abstract:
Soft chemistry synthesis and electrochemical properties via Li0.5La0.5TiO3 (LLTO) fast ionic conductor modification for LiFePO4 cathode material of Li-ion battery were investigated. LiFePO4 was synthesized via solvothermal method, LLTO powder was synthesized via sol-gel method, LiFePO4 was modified by LLTO with the proportion of 1%~4%(w/w) via alcohol suspension mixing method, and the composite cathode materials of thin-wall cellular characteristic self-assembly LiFePO4 modified by spherical LLTO nano-particles were acquired. The effects of LLTO modified proportion on charge and discharge specific capacity, cycle performance and reversibility were studied by charge/discharge test, AC impedance test and cyclic voltammetry test. The results indicate when LLTO modified proportion is 3% (w/w), the discharge specific capacity increases by 29.7% in the current rate of 2C and increases by 31.6% in the current rate of 5C, the capacity loss rate after 30 charge/discharge cycles decreases by 4.13% compared to unmodified condition, and the potential difference between redox peaks in cyclic voltammetry curve is only 0.117 V. LiFePO4 modified by LLTO with proportion of 3% significantly improves the current rate capability and cycle performance of Li-ion battery, and also improves the low temperature performance.
Soft chemistry synthesis and electrochemical properties via Li0.5La0.5TiO3 (LLTO) fast ionic conductor modification for LiFePO4 cathode material of Li-ion battery were investigated. LiFePO4 was synthesized via solvothermal method, LLTO powder was synthesized via sol-gel method, LiFePO4 was modified by LLTO with the proportion of 1%~4%(w/w) via alcohol suspension mixing method, and the composite cathode materials of thin-wall cellular characteristic self-assembly LiFePO4 modified by spherical LLTO nano-particles were acquired. The effects of LLTO modified proportion on charge and discharge specific capacity, cycle performance and reversibility were studied by charge/discharge test, AC impedance test and cyclic voltammetry test. The results indicate when LLTO modified proportion is 3% (w/w), the discharge specific capacity increases by 29.7% in the current rate of 2C and increases by 31.6% in the current rate of 5C, the capacity loss rate after 30 charge/discharge cycles decreases by 4.13% compared to unmodified condition, and the potential difference between redox peaks in cyclic voltammetry curve is only 0.117 V. LiFePO4 modified by LLTO with proportion of 3% significantly improves the current rate capability and cycle performance of Li-ion battery, and also improves the low temperature performance.
2018, 34(7): 1327-1332
doi: 10.11862/CJIC.2018.177
Abstract:
Rhombohedral phase Mn-based Prussian white materials were synthesized by high-temperature coprecipitation method and the effect of synthesis temperature on the microstructure and electrochemical performance of the products was investigated. It is found that the crystallinity, particle size and Na-insertion capacity increase obviously with the increasing synthesis temperature. At a synthesis temperature of 90℃, the first charge and discharge capacities of the product reach 142 and 139 mAh·g-1 at 15 mA·g-1. After 300 cycles at 30 mA·g-1 and 600 cycles at 50 mA·g-1, the discharge capacities are kept at 111 and 89 mAh·g-1, respectively.
Rhombohedral phase Mn-based Prussian white materials were synthesized by high-temperature coprecipitation method and the effect of synthesis temperature on the microstructure and electrochemical performance of the products was investigated. It is found that the crystallinity, particle size and Na-insertion capacity increase obviously with the increasing synthesis temperature. At a synthesis temperature of 90℃, the first charge and discharge capacities of the product reach 142 and 139 mAh·g-1 at 15 mA·g-1. After 300 cycles at 30 mA·g-1 and 600 cycles at 50 mA·g-1, the discharge capacities are kept at 111 and 89 mAh·g-1, respectively.
2018, 34(7): 1333-1340
doi: 10.11862/CJIC.2018.174
Abstract:
The surface modification of LiNi0.8Co0.15Al0.05O2 (NCA) material was conducted by FePO4 coating through a liquid synthetic process. The excellent structural and thermal stability of FePO4 was utilized to improve the long-term reliability and safety of NCA material. The different electrochemical properties of NCA material caused by different coating amount were intensively studied. The FePO4 coating layer is able to prevent the side reaction between NCA particles and electrolytes, suppress the transition metal dissolve from the layered structure, and maintain the long-term stability. The optimum coating content of FePO4 is 1.0% (w/w) best overall performances can be achieved in this situation, after 800 charge-discharge cycles, the capacity retention rate is still as high as 95%. After 100 days storage at 25℃, the capacity retention tate maintains higher than 95%, the energy density, service life and safety of NCA materials are well balanced after modification.
The surface modification of LiNi0.8Co0.15Al0.05O2 (NCA) material was conducted by FePO4 coating through a liquid synthetic process. The excellent structural and thermal stability of FePO4 was utilized to improve the long-term reliability and safety of NCA material. The different electrochemical properties of NCA material caused by different coating amount were intensively studied. The FePO4 coating layer is able to prevent the side reaction between NCA particles and electrolytes, suppress the transition metal dissolve from the layered structure, and maintain the long-term stability. The optimum coating content of FePO4 is 1.0% (w/w) best overall performances can be achieved in this situation, after 800 charge-discharge cycles, the capacity retention rate is still as high as 95%. After 100 days storage at 25℃, the capacity retention tate maintains higher than 95%, the energy density, service life and safety of NCA materials are well balanced after modification.
2018, 34(7): 1249-1260
doi: 10.11862/CJIC.2018.166
Abstract:
We propose a novel method using cetyltrimethyl ammonium bromide (CTAB) as soft template followed by successive graphitization and activation of pomelo peel to get a new biomass-derived hierarchical porous carbon (HPC). The as-obtained HPC possesses a high specific area of 1 813 m2·g-1 with abundant mesopores structure, which is larger than that of 1 184 m2·g-1 for the contrast of the porous carbon (PC) prepared without CTAB. X-ray photoelectron spectroscopy (XPS) analysis presents the oxygen doped amount for HPC is larger than that for PC, which could arise a high pseudocapacitance. In addition, the HPC also shows better electrochemical performance than PC, when utilized as an electrode material in supercapacitor. At a current density of 0.5 A·g-1, the specific capacitance of HPC is up to 285 F·g-1 in 1 mol·L-1 KOH solution. Further investigation based on two-electrode cell suggests good performance with high rate capability and relative stability. Such excellent performance should be attributed to the synergistic effect of large specific surface area, high O-doping content and reasonable pore-size distribution.
We propose a novel method using cetyltrimethyl ammonium bromide (CTAB) as soft template followed by successive graphitization and activation of pomelo peel to get a new biomass-derived hierarchical porous carbon (HPC). The as-obtained HPC possesses a high specific area of 1 813 m2·g-1 with abundant mesopores structure, which is larger than that of 1 184 m2·g-1 for the contrast of the porous carbon (PC) prepared without CTAB. X-ray photoelectron spectroscopy (XPS) analysis presents the oxygen doped amount for HPC is larger than that for PC, which could arise a high pseudocapacitance. In addition, the HPC also shows better electrochemical performance than PC, when utilized as an electrode material in supercapacitor. At a current density of 0.5 A·g-1, the specific capacitance of HPC is up to 285 F·g-1 in 1 mol·L-1 KOH solution. Further investigation based on two-electrode cell suggests good performance with high rate capability and relative stability. Such excellent performance should be attributed to the synergistic effect of large specific surface area, high O-doping content and reasonable pore-size distribution.
