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2015 Volume 31 Issue 3
2015, (3): 429-438
doi: 10.11862/CJIC.2015.101
Abstract:
The rGO/ZnO (reduced graphite oxide/ZnO) composite films were synthesized by using different reduction treated graphite oxides (GOs) as precursors, and then their visible-light excitation photoelectric conversion performance was investigated. In this work, we used the two reducing agents, KOH or NaBH4, to reduce graphite oxide, then the reduced graphite oxide was mixed with zinc oxide sol. rGO/ZnO composite films were prepared by spin-coating and heat treatment on FTO(fluorine-doped tin oxide)conductive glass substrates. The as-prepared samples were characterized by XRD, FTIR, FE-SEM, XPS, UV-Vis, etc. Pretreatment process of graphite oxide had a great influence on the structure of composite films, reduction treatment by NaBH4 was more conducive to form a uniform thin film. Photocurrent test results showed that different composite films can produce photocurrent under visible-light irradiation, the principle was photo-excited electron transition from rGO to ZnO to achieve the separation of photo-generated carriers. The GO after NaBH4-reduction with ZnO composite film showed the largest photocurrent density with a value of 6×10-7 A·cm-2.
The rGO/ZnO (reduced graphite oxide/ZnO) composite films were synthesized by using different reduction treated graphite oxides (GOs) as precursors, and then their visible-light excitation photoelectric conversion performance was investigated. In this work, we used the two reducing agents, KOH or NaBH4, to reduce graphite oxide, then the reduced graphite oxide was mixed with zinc oxide sol. rGO/ZnO composite films were prepared by spin-coating and heat treatment on FTO(fluorine-doped tin oxide)conductive glass substrates. The as-prepared samples were characterized by XRD, FTIR, FE-SEM, XPS, UV-Vis, etc. Pretreatment process of graphite oxide had a great influence on the structure of composite films, reduction treatment by NaBH4 was more conducive to form a uniform thin film. Photocurrent test results showed that different composite films can produce photocurrent under visible-light irradiation, the principle was photo-excited electron transition from rGO to ZnO to achieve the separation of photo-generated carriers. The GO after NaBH4-reduction with ZnO composite film showed the largest photocurrent density with a value of 6×10-7 A·cm-2.
2015, (3): 439-445
doi: 10.11862/CJIC.2015.043
Abstract:
To explore the similarities and differences of hydrogen generation performance of silicon nanowires array (SiNWs array) photocathode prepared by different methods, we adopted two-step metal-catalyzed electroless etching method (TMCEE), one-step metal-catalyzed electroless etching method (OMCEE) and anodic oxidation etching method (AOE) to fabricate silicon nanowires array as a photocathode material for photoelectrochemical hydrogen generation. Comparing with morphology, crystalline, anti-reflection characterization by FESEM, XRD and UV-Vis-IR DRS means, SiNWs array by TMCEE maintained better crystal structure and less surface defects than the samples prepared by the other two methods. Photoelectrochemical tests showed that the performance of SiNWs array by TMCEE was optimal. The photocurrent density value of SiNWs array by TMCEE was 4 times than the one by OMCEE, and 40 times than the one by AOE. The charge transfer resistance of SiNWs array by TMCEE was only 1/3 of SiNWs array by OMCEE, and 1/1 000 of SiNWs array by AOE.
To explore the similarities and differences of hydrogen generation performance of silicon nanowires array (SiNWs array) photocathode prepared by different methods, we adopted two-step metal-catalyzed electroless etching method (TMCEE), one-step metal-catalyzed electroless etching method (OMCEE) and anodic oxidation etching method (AOE) to fabricate silicon nanowires array as a photocathode material for photoelectrochemical hydrogen generation. Comparing with morphology, crystalline, anti-reflection characterization by FESEM, XRD and UV-Vis-IR DRS means, SiNWs array by TMCEE maintained better crystal structure and less surface defects than the samples prepared by the other two methods. Photoelectrochemical tests showed that the performance of SiNWs array by TMCEE was optimal. The photocurrent density value of SiNWs array by TMCEE was 4 times than the one by OMCEE, and 40 times than the one by AOE. The charge transfer resistance of SiNWs array by TMCEE was only 1/3 of SiNWs array by OMCEE, and 1/1 000 of SiNWs array by AOE.
2015, (3): 446-451
doi: 10.11862/CJIC.2015.092
Abstract:
Relying on the density functional theory(DFT), the structural stability and field emission performance of Cs/graphene compound with different Cs coverage were investigated. The results indicated that the adsorption of single Cs atom on the center site of hexatomic ring is energetically favorable. With the increase of Cs coverage, the adsorption interaction between Cs and graphene are gradually enhanced, (4×4)R 0° and (2×2)R 0° structures are stable. Due to the modification effect of Cs metals, the work function of Cs/graphene system decreases obviously, and it is continuously reduced with increasing of Cs coverage. The computational results of the density of states (DOSs) identified that the reduction of the work function is mainly related to the electron transfer between Cs and graphene. With increasing of Cs coverage, the electronic states will shift to a lower energy position, leading to the increase of Fermi energy and the reduction of work function.
Relying on the density functional theory(DFT), the structural stability and field emission performance of Cs/graphene compound with different Cs coverage were investigated. The results indicated that the adsorption of single Cs atom on the center site of hexatomic ring is energetically favorable. With the increase of Cs coverage, the adsorption interaction between Cs and graphene are gradually enhanced, (4×4)R 0° and (2×2)R 0° structures are stable. Due to the modification effect of Cs metals, the work function of Cs/graphene system decreases obviously, and it is continuously reduced with increasing of Cs coverage. The computational results of the density of states (DOSs) identified that the reduction of the work function is mainly related to the electron transfer between Cs and graphene. With increasing of Cs coverage, the electronic states will shift to a lower energy position, leading to the increase of Fermi energy and the reduction of work function.
2015, (3): 452-458
doi: 10.11862/CJIC.2015.083
Abstract:
The series Sm3+ as activator and Bi3+ as auxiliary activator precursor Ca1-x-ySmxBiySiO3 were synthesized by hydrothermal synthesis. After calcined at 1 100 ℃ the precursors became series of orange-reddish emitting phosphors. The phase structure, morphology and luminescent properties of the as-synthesized samples were characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscope and fluorescence spectrophotometer respectively. The results indicate that samples was an eutectic mixture which contain triclinic CaSiO3 and cristobalite SiO2. The emission spectra of Ca1-x-ySmxBiySiO3 phosphors exhibit three main peaks at 566, 606, 650 nm assigned to the 4G5/2→6HJ/2 (J=5, 7, 9) transitions of Sm3+ under 405 nm excited radiation. The excitation spectra of Ca1-x-ySmxBiySiO3 phosphors reveal intensive excitation bands at 405 nm, which match with near-UV LED chips. The luminescence intensity firstly increases with increasing of Sm3+ concentration, and then decreases. The emission reaches the maximum intensity at Sm3+ doped amount of 3% mole fraction, and the concentration quenching mechanism is the electric dipole-electric dipole interaction. When the amount is 0.3%~1.5% mole fraction, Bi3+ have sensitized effect on the luminescence intensity of Ca0.97Sm0.03SiO3. So the optimum mole fraction of Sm3+ and Bi3+ were 3% and 0.5%, respectively.
The series Sm3+ as activator and Bi3+ as auxiliary activator precursor Ca1-x-ySmxBiySiO3 were synthesized by hydrothermal synthesis. After calcined at 1 100 ℃ the precursors became series of orange-reddish emitting phosphors. The phase structure, morphology and luminescent properties of the as-synthesized samples were characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscope and fluorescence spectrophotometer respectively. The results indicate that samples was an eutectic mixture which contain triclinic CaSiO3 and cristobalite SiO2. The emission spectra of Ca1-x-ySmxBiySiO3 phosphors exhibit three main peaks at 566, 606, 650 nm assigned to the 4G5/2→6HJ/2 (J=5, 7, 9) transitions of Sm3+ under 405 nm excited radiation. The excitation spectra of Ca1-x-ySmxBiySiO3 phosphors reveal intensive excitation bands at 405 nm, which match with near-UV LED chips. The luminescence intensity firstly increases with increasing of Sm3+ concentration, and then decreases. The emission reaches the maximum intensity at Sm3+ doped amount of 3% mole fraction, and the concentration quenching mechanism is the electric dipole-electric dipole interaction. When the amount is 0.3%~1.5% mole fraction, Bi3+ have sensitized effect on the luminescence intensity of Ca0.97Sm0.03SiO3. So the optimum mole fraction of Sm3+ and Bi3+ were 3% and 0.5%, respectively.
2015, (3): 459-464
doi: 10.11862/CJIC.2015.074
Abstract:
Under the role of CTAB, different size ZnS spherical-like particles were fabricated by hydrothermal method. The crystal structure, morphology, composition and optical property of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray energy spectrum (EDS), UV-Vis absorption spectrum and photoluminescence spectrum (PL). Photocatalytic activities were evaluated by degradation of MB solution. The results show that ZnS nanoparticles were formed by aggregation of crystal nucleus under the role of CTAB. With the increase of reaction time, the size of ZnS particles increased to 500 nm, however, the crystal structure of product has no change. With the increase of particle size, the UV-Vis absorption peak of samples shifted from 418 to 362 nm and the PL intensity further increased. Finally, the photocatalytic activity presented that fabricated ZnS nanoparticles with reaction time 12 h showed best photcatalytic performance.
Under the role of CTAB, different size ZnS spherical-like particles were fabricated by hydrothermal method. The crystal structure, morphology, composition and optical property of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray energy spectrum (EDS), UV-Vis absorption spectrum and photoluminescence spectrum (PL). Photocatalytic activities were evaluated by degradation of MB solution. The results show that ZnS nanoparticles were formed by aggregation of crystal nucleus under the role of CTAB. With the increase of reaction time, the size of ZnS particles increased to 500 nm, however, the crystal structure of product has no change. With the increase of particle size, the UV-Vis absorption peak of samples shifted from 418 to 362 nm and the PL intensity further increased. Finally, the photocatalytic activity presented that fabricated ZnS nanoparticles with reaction time 12 h showed best photcatalytic performance.
2015, (3): 465-471
doi: 10.11862/CJIC.2015.079
Abstract:
Zeolitic imidazolate framework-90 (ZIF-90) sol-gel and ZIF-90 crystal membrane were prepared. Then silver nanoparticles(Ag NPs) were hosted in the ZIF-90 sol-gel or on the ZIF-90 crystal membrane to form Ag@ZIF-90 composite or Ag/ZIF-90 self-assembled membrane. The Ag@ZIF-90 composite and Ag/ZIF-90 self-assembled membrane were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show their morphorogies and structural features. Rhodamine 6G (R 6G) was used as a detection molecule to test the surface enhanced Raman scattering (SERS) performance of Ag@ZIF-90 composite and Ag/ZIF-90 self-assembled membrane. The SERS signal of R 6G on Ag/ZIF-90 self-assembled membrane was much higher than that on Ag@ZIF-90 composite and the background peak of ZIF-90 did not affect the SERS detection. The Ag/ZIF-90 self-assembled membrane was a promising active SERS substrate, which can be applied in the trace detection of pesticide residue.
Zeolitic imidazolate framework-90 (ZIF-90) sol-gel and ZIF-90 crystal membrane were prepared. Then silver nanoparticles(Ag NPs) were hosted in the ZIF-90 sol-gel or on the ZIF-90 crystal membrane to form Ag@ZIF-90 composite or Ag/ZIF-90 self-assembled membrane. The Ag@ZIF-90 composite and Ag/ZIF-90 self-assembled membrane were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show their morphorogies and structural features. Rhodamine 6G (R 6G) was used as a detection molecule to test the surface enhanced Raman scattering (SERS) performance of Ag@ZIF-90 composite and Ag/ZIF-90 self-assembled membrane. The SERS signal of R 6G on Ag/ZIF-90 self-assembled membrane was much higher than that on Ag@ZIF-90 composite and the background peak of ZIF-90 did not affect the SERS detection. The Ag/ZIF-90 self-assembled membrane was a promising active SERS substrate, which can be applied in the trace detection of pesticide residue.
2015, (3): 472-478
doi: 10.11862/CJIC.2015.066
Abstract:
Pure spinel Co3O4 powders with different morphologies were synthesized by hydrothermal-pyrolysis methods using cobalt chloride (CoCl2) and sodium carbonate (Na2O3) as the raw materials and sodium oleate (SOA) as the surfactant. The reaction process was followed by TG-DTA, XRD and SEM. The effect of hydrothermal time on the structure, the state of the products and the influence of structure on the photocatalytic performance were studied. The reaction mechanism was suggested. The results indicate that the hydrothermal time is the key to the morphology of the product. The catalytic performance is mainly related to the morphology of the final products.
Pure spinel Co3O4 powders with different morphologies were synthesized by hydrothermal-pyrolysis methods using cobalt chloride (CoCl2) and sodium carbonate (Na2O3) as the raw materials and sodium oleate (SOA) as the surfactant. The reaction process was followed by TG-DTA, XRD and SEM. The effect of hydrothermal time on the structure, the state of the products and the influence of structure on the photocatalytic performance were studied. The reaction mechanism was suggested. The results indicate that the hydrothermal time is the key to the morphology of the product. The catalytic performance is mainly related to the morphology of the final products.
2015, (3): 479-484
doi: 10.11862/CJIC.2015.082
Abstract:
After heated at 400 ℃, the activated silica gel reacted with silicon tetrachloride to obtain chlorinated silica gel in anhydrous tetrahydrofuran. And a modified silica gel with carbonyl and amino groups on its surface was obtained by the reaction between chlorinated silica gel and acetamide. The modification has good coordination ability to Fe3+, and a supported catalyst with catalytic active site of Fe3+ evenly distributed was then prepared by coordination between Fe3+ and the surface organic modified silica gel. The synthesized catalyst has good catalytic oxidation performance to formaldehyde, and a maximum conversion of formaldehyde is about 91.3%.
After heated at 400 ℃, the activated silica gel reacted with silicon tetrachloride to obtain chlorinated silica gel in anhydrous tetrahydrofuran. And a modified silica gel with carbonyl and amino groups on its surface was obtained by the reaction between chlorinated silica gel and acetamide. The modification has good coordination ability to Fe3+, and a supported catalyst with catalytic active site of Fe3+ evenly distributed was then prepared by coordination between Fe3+ and the surface organic modified silica gel. The synthesized catalyst has good catalytic oxidation performance to formaldehyde, and a maximum conversion of formaldehyde is about 91.3%.
2015, (3): 485-492
doi: 10.11862/CJIC.2015.081
Abstract:
The structure changes of C16TAB/GO intercalation compounds about the number of cetyl trimethyl ammonium bromide(C16TAB) molecules were investigated by molecular simulation method. The arrangement modes of C16TAB molecules in the interlayer of GO were discussed, and the simulation results were verified by the experimental data. The simulation results show that the layer spacing of the structural model of GO is 0.849 nm; the layer spacing of C16TAB/GO intercalation compounds increases gradually by five ladderlike style with the increase of the number of C16TAB molecules. The layer spacing of each ladder are 1.56, 1.98, 2.33, 2.76 and 3.40 nm, and the number of C16TAB molecules is up to 28 when the intercalation is saturated. The experimental results show that the layer spacing of C16TAB/GO intercalation compounds increases gradually with the increase of the number of C16TAB molecules and the saturation value is 3.40 nm, so the experimental results are in good agreement with simulation results. The possible arrangement modes of C16TAB molecules in the interlayer of GO are 1~5 layers lateral arrangement or lateral monolayer, paraffin-type monolayer and vertical monolayer, and the optimal arrangement modes of C16TAB molecules in the interlayer of GO are 1~5 layers lateral arrangement according to the result of energy and structure.
The structure changes of C16TAB/GO intercalation compounds about the number of cetyl trimethyl ammonium bromide(C16TAB) molecules were investigated by molecular simulation method. The arrangement modes of C16TAB molecules in the interlayer of GO were discussed, and the simulation results were verified by the experimental data. The simulation results show that the layer spacing of the structural model of GO is 0.849 nm; the layer spacing of C16TAB/GO intercalation compounds increases gradually by five ladderlike style with the increase of the number of C16TAB molecules. The layer spacing of each ladder are 1.56, 1.98, 2.33, 2.76 and 3.40 nm, and the number of C16TAB molecules is up to 28 when the intercalation is saturated. The experimental results show that the layer spacing of C16TAB/GO intercalation compounds increases gradually with the increase of the number of C16TAB molecules and the saturation value is 3.40 nm, so the experimental results are in good agreement with simulation results. The possible arrangement modes of C16TAB molecules in the interlayer of GO are 1~5 layers lateral arrangement or lateral monolayer, paraffin-type monolayer and vertical monolayer, and the optimal arrangement modes of C16TAB molecules in the interlayer of GO are 1~5 layers lateral arrangement according to the result of energy and structure.
2015, (3): 493-500
doi: 10.11862/CJIC.2015.065
Abstract:
A series of sulfonic acid-functionalized silica-pillared zirconium phosphate materials with ordered layer structure were synthesized using the hexadecylamine (HDA) intercalated α-ZrP as raw material, dodecyl dimethyl benzyl ammonium chloride (DDBAC) as templet agent, tetraethyl orthosilicate (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) as the mixed silicon source, hydrogen peroxide as oxidant. The structure of the sulfonic acid-functionalized materials were characterized by XRD, SEM, N2 adsorption-desorption and FTIR. Pillared layered structure and pore structure were optimized by adjusting the length of long chain in organic amine and templet. Meanwhile, the specific surface area and pore diameter of the resulting materials are about 163 m2·g-1 and 2.17 nm, and the materials have ordered layer structure and pillared structure. The acid site property was adjusted, and the number of sulfonic acid groups and the total acid value respectively increase to 2.71 mmol·g-1 and 5.20 mmol·g-1. Due to the special steric effect and abundant Brönsted acid sites, the material shows excellent performance with 95.74% conversion in the esterification of citric acid with n-butanol.
A series of sulfonic acid-functionalized silica-pillared zirconium phosphate materials with ordered layer structure were synthesized using the hexadecylamine (HDA) intercalated α-ZrP as raw material, dodecyl dimethyl benzyl ammonium chloride (DDBAC) as templet agent, tetraethyl orthosilicate (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) as the mixed silicon source, hydrogen peroxide as oxidant. The structure of the sulfonic acid-functionalized materials were characterized by XRD, SEM, N2 adsorption-desorption and FTIR. Pillared layered structure and pore structure were optimized by adjusting the length of long chain in organic amine and templet. Meanwhile, the specific surface area and pore diameter of the resulting materials are about 163 m2·g-1 and 2.17 nm, and the materials have ordered layer structure and pillared structure. The acid site property was adjusted, and the number of sulfonic acid groups and the total acid value respectively increase to 2.71 mmol·g-1 and 5.20 mmol·g-1. Due to the special steric effect and abundant Brönsted acid sites, the material shows excellent performance with 95.74% conversion in the esterification of citric acid with n-butanol.
2015, (3): 501-508
doi: 10.11862/CJIC.2015.096
Abstract:
The kaolinite/γ-aminopropyltriethoxysilane (K/APTES) was prepared with a direct displacement intercalation method by using kaolinite/methanol intercalation complex as an intermediate.The samples were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and TEM analysis.Analysis suggested that the amidogen of APTES forms hydrogen bonds with tetrahedron siloxane and interlayer methoxy group of the kaolinite/methanol intercalation complex. The APTES molecules are arranged in double layer aslant between the kaolinite layers, and the inclination angle is related to the temperature. Because of hydrogen bonds are broken by APTES, the K/APTES intercalation compound appears clear scroll and exfoliation. The kinetic triplet of APTES' deintercalation from K/APTES intercalation complex was calculated by Satava integral method and Achar-Brindley-Sharp-Wendworth differential method. The activation energy E is 197.8 kJ·mol-1, the logarithm of pre-exponential factor lg(A/s-1) is 14.60. The mechanism function is G(α)=α+(1-α)ln(1-α) and f(α)=[-ln(1-α)]-1.
The kaolinite/γ-aminopropyltriethoxysilane (K/APTES) was prepared with a direct displacement intercalation method by using kaolinite/methanol intercalation complex as an intermediate.The samples were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and TEM analysis.Analysis suggested that the amidogen of APTES forms hydrogen bonds with tetrahedron siloxane and interlayer methoxy group of the kaolinite/methanol intercalation complex. The APTES molecules are arranged in double layer aslant between the kaolinite layers, and the inclination angle is related to the temperature. Because of hydrogen bonds are broken by APTES, the K/APTES intercalation compound appears clear scroll and exfoliation. The kinetic triplet of APTES' deintercalation from K/APTES intercalation complex was calculated by Satava integral method and Achar-Brindley-Sharp-Wendworth differential method. The activation energy E is 197.8 kJ·mol-1, the logarithm of pre-exponential factor lg(A/s-1) is 14.60. The mechanism function is G(α)=α+(1-α)ln(1-α) and f(α)=[-ln(1-α)]-1.
2015, (3): 509-513
doi: 10.11862/CJIC.2015.078
Abstract:
Variance lithium content MOF-5 (xLi-MOF-5, x=0, 1, 3, 5) were prepared by using solvothermal method. Lithium cation can be incorporated with MOF-5 during its crystallization process. The experiment demonstrated that lithium incorporation have significantly led different structure and surface chemistry in MOF-5. Different xLi-MOF-5 can reduce framework interpenetration level dissimilarly and lead material with substantially different adsorption separation properties. The 3Li-MOF-5 shows the highest CO2 capacity (5.47 mmol·g-1) and the best selectivity on 40% CO2/60% CH4 mixed gas.
Variance lithium content MOF-5 (xLi-MOF-5, x=0, 1, 3, 5) were prepared by using solvothermal method. Lithium cation can be incorporated with MOF-5 during its crystallization process. The experiment demonstrated that lithium incorporation have significantly led different structure and surface chemistry in MOF-5. Different xLi-MOF-5 can reduce framework interpenetration level dissimilarly and lead material with substantially different adsorption separation properties. The 3Li-MOF-5 shows the highest CO2 capacity (5.47 mmol·g-1) and the best selectivity on 40% CO2/60% CH4 mixed gas.
2015, (3): 514-520
doi: 10.11862/CJIC.2015.077
Abstract:
Mesoporous CdS-pillared titanoniobate nanohybrids were successfully prepared via an exfoliation-restacking route. It was found that as-prepared CdS-TiNbO5 nanohybrids have an interlayer spacing of 1.19 nm and high specific surface areas of about 93 m2·g-1. The nanohybrids showed a remarkable photocatalytic hydrogen-evolution activity in water splitting. When the molar ratio of CdS and titanoniobate nanosheets was equal to 1:2, the H2-evolution rate reached 231 and 184 μmol·h-1·g-1 under irradiation of 300 W Xe lamp and visible light, which is 8.6 and 9.7 times as high as the blank CdS. The improvement of photocatalytic activity is predominantly ascribed to the enlarged specific surface area and the effective spatial separation of photogenerated carriers between the host and guest.
Mesoporous CdS-pillared titanoniobate nanohybrids were successfully prepared via an exfoliation-restacking route. It was found that as-prepared CdS-TiNbO5 nanohybrids have an interlayer spacing of 1.19 nm and high specific surface areas of about 93 m2·g-1. The nanohybrids showed a remarkable photocatalytic hydrogen-evolution activity in water splitting. When the molar ratio of CdS and titanoniobate nanosheets was equal to 1:2, the H2-evolution rate reached 231 and 184 μmol·h-1·g-1 under irradiation of 300 W Xe lamp and visible light, which is 8.6 and 9.7 times as high as the blank CdS. The improvement of photocatalytic activity is predominantly ascribed to the enlarged specific surface area and the effective spatial separation of photogenerated carriers between the host and guest.
2015, (3): 521-528
doi: 10.11862/CJIC.2015.080
Abstract:
BiOI/NaBiO3 heterostructure photocatalysts were synthesized using HI as etching agents to react with NaBiO3 by a heating condensate reflux method according to surface chemical etching principle. Several characterization tools including X-ray powder diffraction (XRD), scanning electron microscope (SEM) and UV-Vis diffuse reflectance spectra (UV-Vis DRS) were employed to study the phase structures, morphologies and optical properties of the as-prepared samples respectively. From the degradation of Rhodamine B(RhB) under visible light irradiation experimental results, we can obtained that the absorption capacity of as-prepared samples were enhanced with increasing the BiOI amounts in the BiOI/NaBiO3 heterostructures until the BiOI/NaBiO3 ratio is 79.62%. With increasing BiOI content, the photocatalytic activity enhanced gradually and then decreased. As the BiOI content increase to 17.34%, the highest photocatalytic activity could be achieved, and the RhB almost faded completely with the time increasing to 100 min. The results show that the adsorption ability is only a factor not all to promote the photocatalytic ability. The EVB of NaBiO3 and BiOI were calculated to be 2.23 and 2.41 eV and the ECB of NaBiO3 and BiOI were -0.23 and 0.46 eV by the UV-Vis DRS method respectively. To evaluate the roles of reactive species during photocatalysis, different scavengers including benzoquinone, isopropyl alcohol and methanol were adopted as the traps for O2-, OH and h+ for RhB degradation. The results suggesting that h+ played major role for RhB degradation. Terephthalic acid photoluminescence (TA-PL) probing test demonstrated that OH could be negligible also. According to the band gap structure of BiOI/NaBiO3, the effects of scavengers and the PL experimental results, a possible charge separation processes between BiOI and NaBiO3, and the pathway for the photocatalytic activity enhancement mechanism was proposed. The heterojunction at the interface between p-BiOI and n-NaBiO3 can efficiently reduce the recombination of photogenerated electron-hole pairs and which accounts for the enhancement of photocatalytic activity. Form the analysis of potential, it is theoretically reasonable that the photocatalytic degradation of RhB could be attributed to the reaction of hole directly rather than OH and O2- radicals.
BiOI/NaBiO3 heterostructure photocatalysts were synthesized using HI as etching agents to react with NaBiO3 by a heating condensate reflux method according to surface chemical etching principle. Several characterization tools including X-ray powder diffraction (XRD), scanning electron microscope (SEM) and UV-Vis diffuse reflectance spectra (UV-Vis DRS) were employed to study the phase structures, morphologies and optical properties of the as-prepared samples respectively. From the degradation of Rhodamine B(RhB) under visible light irradiation experimental results, we can obtained that the absorption capacity of as-prepared samples were enhanced with increasing the BiOI amounts in the BiOI/NaBiO3 heterostructures until the BiOI/NaBiO3 ratio is 79.62%. With increasing BiOI content, the photocatalytic activity enhanced gradually and then decreased. As the BiOI content increase to 17.34%, the highest photocatalytic activity could be achieved, and the RhB almost faded completely with the time increasing to 100 min. The results show that the adsorption ability is only a factor not all to promote the photocatalytic ability. The EVB of NaBiO3 and BiOI were calculated to be 2.23 and 2.41 eV and the ECB of NaBiO3 and BiOI were -0.23 and 0.46 eV by the UV-Vis DRS method respectively. To evaluate the roles of reactive species during photocatalysis, different scavengers including benzoquinone, isopropyl alcohol and methanol were adopted as the traps for O2-, OH and h+ for RhB degradation. The results suggesting that h+ played major role for RhB degradation. Terephthalic acid photoluminescence (TA-PL) probing test demonstrated that OH could be negligible also. According to the band gap structure of BiOI/NaBiO3, the effects of scavengers and the PL experimental results, a possible charge separation processes between BiOI and NaBiO3, and the pathway for the photocatalytic activity enhancement mechanism was proposed. The heterojunction at the interface between p-BiOI and n-NaBiO3 can efficiently reduce the recombination of photogenerated electron-hole pairs and which accounts for the enhancement of photocatalytic activity. Form the analysis of potential, it is theoretically reasonable that the photocatalytic degradation of RhB could be attributed to the reaction of hole directly rather than OH and O2- radicals.
2015, (3): 529-535
doi: 10.11862/CJIC.2015.087
Abstract:
Zeolite A membranes were synthesized on 0.8Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3 lead free piezoelectric ceramics surface via hydro-thermal synthesis in micro-emulsion solution and clear solution. The zeolite seeds were connected with ceramics surfaces modified by chemical method. The synthesized zeolites and membranes were characterized using XRD, SEM and FTIR. The amount of methane adsorption were measured by piezoelectric resonator method. The results show the A-type zeolite single phase is obtained both by micro-emulsion solution and clear solution. The first coating times of them are designed as 6 and 9 h separately, and the thickness and morphology of zeolite membranes are changed with different coating times. The sensitivity of piezoelectric vibrator can be achieved to 59 Hz/1%CH4 and 68 Hz/1%CH4 using zeolite A membranes obtained by micro-emulsion solution and clear solution as adsorption layer.
Zeolite A membranes were synthesized on 0.8Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3 lead free piezoelectric ceramics surface via hydro-thermal synthesis in micro-emulsion solution and clear solution. The zeolite seeds were connected with ceramics surfaces modified by chemical method. The synthesized zeolites and membranes were characterized using XRD, SEM and FTIR. The amount of methane adsorption were measured by piezoelectric resonator method. The results show the A-type zeolite single phase is obtained both by micro-emulsion solution and clear solution. The first coating times of them are designed as 6 and 9 h separately, and the thickness and morphology of zeolite membranes are changed with different coating times. The sensitivity of piezoelectric vibrator can be achieved to 59 Hz/1%CH4 and 68 Hz/1%CH4 using zeolite A membranes obtained by micro-emulsion solution and clear solution as adsorption layer.
2015, (3): 536-542
doi: 10.11862/CJIC.2015.040
Abstract:
Two homochiral mononuclear spin-crossover iron(Ⅱ) complexes, namely, fac-Λ-[Fe(R-L1)3](ClO4)2 (1), fac-Λ-[Fe(R-L2)3](ClO4)2 (2) have been successfully synthesized by subcomponent self-assembly of Fe(ClO4)2, 4-(imidazole-2-carboxaldehyde)butyronitrile and optical phenylethylamine derivatives. The two complexes have been determined by single-crystal X-ray diffraction analysis, elemental analysis, IR spectra, 1H NMR spectra, UV spectra and CD spectra. X-ray crystallography revealed that the iron(Ⅱ) center in 1 and 2 assumed an octahedral coordination environment with six N donor atoms from three unsymmetrical bidentate chiral schiff-base ligands. Each unit contained one [Fe(L)3]2+ cation and two ClO4- anions. [Fe(L)3]2 components were chiral with Λ configuration due to the screw coordination arrangement of the chiral ligand around Fe(Ⅱ) centers. The Fe(Ⅱ)-N bond distances indicated that the Fe(Ⅱ) sites of 1 and 2 were in low-spin state. As for [Fe(L)3]2+, intramolecular π-π interactions were present between phenyl group and imidazole ring of an adjacent ligand. In 1 and 2, 3D supramolecular architectures were formed through intermolecular C-H…π interactions. Circular dichromism spectra confirmed the presence of non-racemic chiral metal centers in solution for complexes 1 and 2. Magnetic measurements revealed that 1 and 2 displayed obviously spin-crossover behaviour at 232 and 250 K, respectively. Complexes 1 and 2 crystallized in the same chiral space group with similar packing modes and intermolecular interactions, therefore their different SCO bahaviors mainly resulted from substitution effect.
Two homochiral mononuclear spin-crossover iron(Ⅱ) complexes, namely, fac-Λ-[Fe(R-L1)3](ClO4)2 (1), fac-Λ-[Fe(R-L2)3](ClO4)2 (2) have been successfully synthesized by subcomponent self-assembly of Fe(ClO4)2, 4-(imidazole-2-carboxaldehyde)butyronitrile and optical phenylethylamine derivatives. The two complexes have been determined by single-crystal X-ray diffraction analysis, elemental analysis, IR spectra, 1H NMR spectra, UV spectra and CD spectra. X-ray crystallography revealed that the iron(Ⅱ) center in 1 and 2 assumed an octahedral coordination environment with six N donor atoms from three unsymmetrical bidentate chiral schiff-base ligands. Each unit contained one [Fe(L)3]2+ cation and two ClO4- anions. [Fe(L)3]2 components were chiral with Λ configuration due to the screw coordination arrangement of the chiral ligand around Fe(Ⅱ) centers. The Fe(Ⅱ)-N bond distances indicated that the Fe(Ⅱ) sites of 1 and 2 were in low-spin state. As for [Fe(L)3]2+, intramolecular π-π interactions were present between phenyl group and imidazole ring of an adjacent ligand. In 1 and 2, 3D supramolecular architectures were formed through intermolecular C-H…π interactions. Circular dichromism spectra confirmed the presence of non-racemic chiral metal centers in solution for complexes 1 and 2. Magnetic measurements revealed that 1 and 2 displayed obviously spin-crossover behaviour at 232 and 250 K, respectively. Complexes 1 and 2 crystallized in the same chiral space group with similar packing modes and intermolecular interactions, therefore their different SCO bahaviors mainly resulted from substitution effect.
2015, (3): 543-547
doi: 10.11862/CJIC.2015.093
Abstract:
The water-soluble CdTe quantum dots were synthesized with Thioglycolicacid (TGA) as stabilizer in the aqueous solution, and the ammonified core /shell nanoparticles coated with TEOS and chitosan were synthesized with reverse microemulsion method. The nanocomposites were connected with DNA by electrostatic adsorption. The property and morphology of these particles were characterized by SEM, TEM, FL, IR, UV and Zeta Potential. The results showed that the amino-modified nanocomposites were synthesized successfully and had high adsorption capacity for DNA.
The water-soluble CdTe quantum dots were synthesized with Thioglycolicacid (TGA) as stabilizer in the aqueous solution, and the ammonified core /shell nanoparticles coated with TEOS and chitosan were synthesized with reverse microemulsion method. The nanocomposites were connected with DNA by electrostatic adsorption. The property and morphology of these particles were characterized by SEM, TEM, FL, IR, UV and Zeta Potential. The results showed that the amino-modified nanocomposites were synthesized successfully and had high adsorption capacity for DNA.
2015, (3): 548-554
doi: 10.11862/CJIC.2015.026
Abstract:
A benzothiazole-based fluorescent probe N-(4-(benzo[d]thiazol-2-yl)phenyl)-2-((2-hydroxyethyl) (pyridin-2-ylmethyl)amino)acetamide (FL) has been synthesized and characterized, and its recognition properties towards various metal ions have been studied by spectrometry. The results showed that FL was highly sensitive and selective to Cu2+, and other metal ions did not interfere with its recognition for Cu2+. The stoichiometry of the complex formation of FL with Cu2+ was determined to be 1:1, and the fluorescence intensity of FL varied almost linearly versus the concentration of Cu2+ (3.8~9.6 μmol·L-1). FL can also be applied to detect Cu2+ in different water samples such as tap and lake water.
A benzothiazole-based fluorescent probe N-(4-(benzo[d]thiazol-2-yl)phenyl)-2-((2-hydroxyethyl) (pyridin-2-ylmethyl)amino)acetamide (FL) has been synthesized and characterized, and its recognition properties towards various metal ions have been studied by spectrometry. The results showed that FL was highly sensitive and selective to Cu2+, and other metal ions did not interfere with its recognition for Cu2+. The stoichiometry of the complex formation of FL with Cu2+ was determined to be 1:1, and the fluorescence intensity of FL varied almost linearly versus the concentration of Cu2+ (3.8~9.6 μmol·L-1). FL can also be applied to detect Cu2+ in different water samples such as tap and lake water.
2015, (3): 555-564
doi: 10.11862/CJIC.2015.091
Abstract:
Three complexes have been obtained by the reaction of metal (Mn(Ⅱ), Cd(Ⅱ)), 5,6-substituted 1,10-phen derivatives with two carboxylic acids, 4,4'-oxybis(benzoic acid)(4,4'-H2oba) and oxalic acid (H2ox). The crystal structures of the resulting complexes, namely {[Mn(4,4'-oba)(Medpq)]Medpq}n (1), [Mn2(4,4'-oba)2(MOPIP)4]·2H2O (2), and [Cd(ox)(MOPIP)2]·2H2O (3) (Medpq=2-methyldipyrido-[3,2-f:2,3'-h]quinoxaline, MOPIP=2-(4-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline]), have been elucidated using their single-crystal X-ray diffraction analysis. Diverse structures are observed for these complexes. Compound 1 contains double chains, which are further stacked via hydrogen bonding interactions to form layers. Compound 2 features dinuclear structures, which are connected by strong π…π and hydrogen bonding interactions to result in layer structures. Compound 3 contains mononuclear structures and extended to chain and layer structures by π…π and hydrogen bonding interactions. The differences among these structures indicate that the size of the rigid chelating ligands and the flexibility of carboxylate have important effects on the structures of their complexes. The fluorescent properties of 2 and 3 were studied in the solid state at room temperature.
Three complexes have been obtained by the reaction of metal (Mn(Ⅱ), Cd(Ⅱ)), 5,6-substituted 1,10-phen derivatives with two carboxylic acids, 4,4'-oxybis(benzoic acid)(4,4'-H2oba) and oxalic acid (H2ox). The crystal structures of the resulting complexes, namely {[Mn(4,4'-oba)(Medpq)]Medpq}n (1), [Mn2(4,4'-oba)2(MOPIP)4]·2H2O (2), and [Cd(ox)(MOPIP)2]·2H2O (3) (Medpq=2-methyldipyrido-[3,2-f:2,3'-h]quinoxaline, MOPIP=2-(4-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline]), have been elucidated using their single-crystal X-ray diffraction analysis. Diverse structures are observed for these complexes. Compound 1 contains double chains, which are further stacked via hydrogen bonding interactions to form layers. Compound 2 features dinuclear structures, which are connected by strong π…π and hydrogen bonding interactions to result in layer structures. Compound 3 contains mononuclear structures and extended to chain and layer structures by π…π and hydrogen bonding interactions. The differences among these structures indicate that the size of the rigid chelating ligands and the flexibility of carboxylate have important effects on the structures of their complexes. The fluorescent properties of 2 and 3 were studied in the solid state at room temperature.
2015, (3): 565-570
doi: 10.11862/CJIC.2015.089
Abstract:
A one-dimensional cyanide-bridged CrⅢ-CuⅡ complex {[Cu(cyclam)][Cr(bpb)(CN)2]2·2H2O}n (cyclam=1, 4,8, 11-tetraazacyclotetradecane, bpb2-=1,2-bis(pyridine-2-carboxamido)-benzenate) (1) has been synthesized by the reaction of building blocks [Cu(cyclam)](ClO4)2 and K[Cr(bpb)(CN)2]. Single crystal X-ray diffraction analysis reveals that complex 1 crystallizes in triclinic space group P1 with a=0.966 73(19) nm, b=1.345 1(3) nm, c= 1.382 0(3) nm, α=77.12(3)°, β=76.93(3)°, γ=82.02(3)°, V=1.699 1(6) nm3, Z=2, Dc=1.567 g·cm-3, μ=1.086 mm-1, F(000)=828, R1=0.041 3, wR2=0.120 0, the structure of complex 1 is a type of polymer with two different metal centers which are alternatively linked by cyanide group. Magnetic investigations indicate that complex 1 exhibits a weak ferromagnetic coupling between CrⅢ and CuⅡ centers through the cyanide bridge.
A one-dimensional cyanide-bridged CrⅢ-CuⅡ complex {[Cu(cyclam)][Cr(bpb)(CN)2]2·2H2O}n (cyclam=1, 4,8, 11-tetraazacyclotetradecane, bpb2-=1,2-bis(pyridine-2-carboxamido)-benzenate) (1) has been synthesized by the reaction of building blocks [Cu(cyclam)](ClO4)2 and K[Cr(bpb)(CN)2]. Single crystal X-ray diffraction analysis reveals that complex 1 crystallizes in triclinic space group P1 with a=0.966 73(19) nm, b=1.345 1(3) nm, c= 1.382 0(3) nm, α=77.12(3)°, β=76.93(3)°, γ=82.02(3)°, V=1.699 1(6) nm3, Z=2, Dc=1.567 g·cm-3, μ=1.086 mm-1, F(000)=828, R1=0.041 3, wR2=0.120 0, the structure of complex 1 is a type of polymer with two different metal centers which are alternatively linked by cyanide group. Magnetic investigations indicate that complex 1 exhibits a weak ferromagnetic coupling between CrⅢ and CuⅡ centers through the cyanide bridge.
2015, (3): 571-579
doi: 10.11862/CJIC.2015.064
Abstract:
A thiolated silica gel was obtained by treating the as-prepared pristine silica gel with γ-mercaptopropyltriethoxysilane through an impregnation route. The FTIR and Raman spectroscopy results indicate that the thiolation of silica gel is achieved by attaching γ-mercaptopropyldiethoxysilane onto the surface of silica gel via a chemical linking. The results for batch removal of Rhodamine B(RhB) from aqueous solution by the thiolated silica gel demonstrate that the thiolated silica gel can effectively adsorb RhB under a wide range of conditions. The data of adsorption kinetics are fitted well with the pseudo-second-order model, and the equilibrium data are well described by the typical Langmuir adsorption isotherm. The thermodynamic derivation shows an exothermic and spontaneous nature of adsorption process with a high value of enthalpy change. The adsorption kinetics, isotherm and thermodynamics suggest a mechanism involving chemisorptions of RhB on thiolated silica gel as confirmed by FTIR and Raman spectroscopy.
A thiolated silica gel was obtained by treating the as-prepared pristine silica gel with γ-mercaptopropyltriethoxysilane through an impregnation route. The FTIR and Raman spectroscopy results indicate that the thiolation of silica gel is achieved by attaching γ-mercaptopropyldiethoxysilane onto the surface of silica gel via a chemical linking. The results for batch removal of Rhodamine B(RhB) from aqueous solution by the thiolated silica gel demonstrate that the thiolated silica gel can effectively adsorb RhB under a wide range of conditions. The data of adsorption kinetics are fitted well with the pseudo-second-order model, and the equilibrium data are well described by the typical Langmuir adsorption isotherm. The thermodynamic derivation shows an exothermic and spontaneous nature of adsorption process with a high value of enthalpy change. The adsorption kinetics, isotherm and thermodynamics suggest a mechanism involving chemisorptions of RhB on thiolated silica gel as confirmed by FTIR and Raman spectroscopy.
2015, (3): 580-584
doi: 10.11862/CJIC.2015.072
Abstract:
A red fluorescence boron-dipyrromethene (BODIPY, BODIPY core=4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dimer 1, which is linked through β-β (2/6) position from a coupling reaction, exhibits efficient energy transfer with 222 nm pseudo Stokes' shift. The BODIPY dimer 1 shows high selectivity and sensitivity towards Fe (Ⅲ) when the ion co-exsists with common interfering metal ions and it may be used as an indicator for Fe3+.
A red fluorescence boron-dipyrromethene (BODIPY, BODIPY core=4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dimer 1, which is linked through β-β (2/6) position from a coupling reaction, exhibits efficient energy transfer with 222 nm pseudo Stokes' shift. The BODIPY dimer 1 shows high selectivity and sensitivity towards Fe (Ⅲ) when the ion co-exsists with common interfering metal ions and it may be used as an indicator for Fe3+.
2015, (3): 585-593
doi: 10.11862/CJIC.2015.086
Abstract:
Two complexes, Cu2(L1)4(CH3OH)2 (1) and Cu2(L2)4(CH3OH)2 (2) (HL1=2-methoxybenzoic acid, HL2=2,3-dimethoxybenzoic acid) were synthesized and characterized by IR spectorscopy, elemental analysis, X-ray powder and X-ray single-crystal diffraction. Complex 1 crystallizes in monoclinic, space group P21/n; Complex 2 crystallizes in triclinic, space group P1. Both of the complexes have dinuclear structure, consisting of two Cu(Ⅱ) cations, four L ligands and two methanol ligands molecules, in which the L ligands are coordinated with copper cations by bidentate bridging coordination mode. The thermal stability of the complexes was investigated, and theoretical study of the complexes was carried out by Density Functional Theory(DFT) B3LYP method using Gaussian 09 program.
Two complexes, Cu2(L1)4(CH3OH)2 (1) and Cu2(L2)4(CH3OH)2 (2) (HL1=2-methoxybenzoic acid, HL2=2,3-dimethoxybenzoic acid) were synthesized and characterized by IR spectorscopy, elemental analysis, X-ray powder and X-ray single-crystal diffraction. Complex 1 crystallizes in monoclinic, space group P21/n; Complex 2 crystallizes in triclinic, space group P1. Both of the complexes have dinuclear structure, consisting of two Cu(Ⅱ) cations, four L ligands and two methanol ligands molecules, in which the L ligands are coordinated with copper cations by bidentate bridging coordination mode. The thermal stability of the complexes was investigated, and theoretical study of the complexes was carried out by Density Functional Theory(DFT) B3LYP method using Gaussian 09 program.
2015, (3): 594-602
doi: 10.11862/CJIC.2015.069
Abstract:
Using Zn(NO3)2·6H2O as raw material, 25% ammonia as complexing agent and NaOH as precipitant, ZnO micro-spheres were synthesized by low temperature complex-precipitate(LTCP) method. The species distribution in the system was also analyzed. XRD and SEM were employed to characterize ZnO samples. The SEM images demonstrate that the uniform micro-spheres are about 2 μm. The morphology of the samples appears as micro-rods and as irregular polyhedrons without addition of NaOH or ammonia. ZnO micro-spheres were hydrophobically modified by varies amounts of cetyltrimethylammonium bromide(CTAB) in order to obtain different contact angles. Meanwhile, the process for surfactant molecules absorption on ZnO micro-spheres surface was discussed. The results of foam stability reveal that 0.03wt% ZnO micro-sphere with surface contact angle of 52.9° makes the greatest contribution to improving the stability of foams.
Using Zn(NO3)2·6H2O as raw material, 25% ammonia as complexing agent and NaOH as precipitant, ZnO micro-spheres were synthesized by low temperature complex-precipitate(LTCP) method. The species distribution in the system was also analyzed. XRD and SEM were employed to characterize ZnO samples. The SEM images demonstrate that the uniform micro-spheres are about 2 μm. The morphology of the samples appears as micro-rods and as irregular polyhedrons without addition of NaOH or ammonia. ZnO micro-spheres were hydrophobically modified by varies amounts of cetyltrimethylammonium bromide(CTAB) in order to obtain different contact angles. Meanwhile, the process for surfactant molecules absorption on ZnO micro-spheres surface was discussed. The results of foam stability reveal that 0.03wt% ZnO micro-sphere with surface contact angle of 52.9° makes the greatest contribution to improving the stability of foams.
2015, (3): 603-610
doi: 10.11862/CJIC.2015.070
Abstract:
Two cadmium supramolecular complexes, [Cd(HMPCA)2(2,2'-bpy)]·2H2O (1) and [Cd(HMPCA)2(phen)]·2.5H2O (2) (H2MPCA=5-methyl-1H-pyrazole-3-carboxylic acid, 2,2'-bpy=2,2'-bipyridine, phen=1,10-phenanthro-line), have been synthesized and characterized by elemental analysis, IR spectra and X-ray diffraction analysis. In 1 and 2, the mononuclear units are expanded to 3D supramolecular structures via O(C, N)-H…O hydrogen bonds, C-H…π interaction and π…π interaction. More interestingly, the water-carboxylate hydrogen bonded chains constructed by lattice water molecules and carboxylate groups play important role in the assembly of two supramolecular complexes. Besides, the thermal and luminescent properties of two complexes were also investigated.
Two cadmium supramolecular complexes, [Cd(HMPCA)2(2,2'-bpy)]·2H2O (1) and [Cd(HMPCA)2(phen)]·2.5H2O (2) (H2MPCA=5-methyl-1H-pyrazole-3-carboxylic acid, 2,2'-bpy=2,2'-bipyridine, phen=1,10-phenanthro-line), have been synthesized and characterized by elemental analysis, IR spectra and X-ray diffraction analysis. In 1 and 2, the mononuclear units are expanded to 3D supramolecular structures via O(C, N)-H…O hydrogen bonds, C-H…π interaction and π…π interaction. More interestingly, the water-carboxylate hydrogen bonded chains constructed by lattice water molecules and carboxylate groups play important role in the assembly of two supramolecular complexes. Besides, the thermal and luminescent properties of two complexes were also investigated.
2015, (3): 611-618
doi: 10.11862/CJIC.2015.098
Abstract:
One monomeric complex [Zn(4,4'-bpy)(Hcmdpca)2(H2O)3]·2H2O (1) and one 1D coordination polymer [Zn(4,4'-bpy)(Hcmdpca)2(H2O)]·3H2O (2) (H2cmdpca=1-carboxymethyl-3,5-dimethyl-1H-pyrazole-4-carboxylic acid, 4,4'-bpy=4,4'-bipyridine) have been synthesized and characterized by elemental analysis, IR spectra, single crystal X-ray diffraction, thermogravimetric analysis. Complexes 1 and 2 all crystallize in the monoclinic system, space group P2/c. In 1, Zn(Ⅱ) ion is located in distorted octahedral coordination geometry, discrete mononucleate units and water molecules are assembled into a 3D network. In 2, each Zn(Ⅱ) ion is located in distorted square-pyramid geometry. Each 4,4'-bpy ligand bridges two adjacent Zn(Ⅱ) ions, forming a 1D chain. These chains and water molecules are connected by hydrogen bonds, forming a 3D supramolecular network. The thermal stability and luminescent properties of the complexes are also investigated.
One monomeric complex [Zn(4,4'-bpy)(Hcmdpca)2(H2O)3]·2H2O (1) and one 1D coordination polymer [Zn(4,4'-bpy)(Hcmdpca)2(H2O)]·3H2O (2) (H2cmdpca=1-carboxymethyl-3,5-dimethyl-1H-pyrazole-4-carboxylic acid, 4,4'-bpy=4,4'-bipyridine) have been synthesized and characterized by elemental analysis, IR spectra, single crystal X-ray diffraction, thermogravimetric analysis. Complexes 1 and 2 all crystallize in the monoclinic system, space group P2/c. In 1, Zn(Ⅱ) ion is located in distorted octahedral coordination geometry, discrete mononucleate units and water molecules are assembled into a 3D network. In 2, each Zn(Ⅱ) ion is located in distorted square-pyramid geometry. Each 4,4'-bpy ligand bridges two adjacent Zn(Ⅱ) ions, forming a 1D chain. These chains and water molecules are connected by hydrogen bonds, forming a 3D supramolecular network. The thermal stability and luminescent properties of the complexes are also investigated.
2015, (3): 619-626
doi: 10.11862/CJIC.2015.084
Abstract:
Using diethylenetriamine (DETA) as coordination agent, a well-defined flower-like cobalt mesocrystal was synthesized rapidly by nanoparticles self assembly in oriented fashion. By adjusting reaction rate and kind of coordination agents, morphologies of cobalt can be transformed from nice-look flower, via poor-look dendrite, to microsphere composed of nanoparticles or nanoplates. DETA plays an important role in the formation process of cobalt mesocrystal. The possible formation mechanism is proposed. The cobalt mesocrystals not only exhibit Co nanocrystals property (an enhanced coercive force being 260 Oe at 300 K), but also have bulk Co property (saturation magnetization being 168 emu·g-1). The synthesis method in large scale is facile and effective with high yield.
Using diethylenetriamine (DETA) as coordination agent, a well-defined flower-like cobalt mesocrystal was synthesized rapidly by nanoparticles self assembly in oriented fashion. By adjusting reaction rate and kind of coordination agents, morphologies of cobalt can be transformed from nice-look flower, via poor-look dendrite, to microsphere composed of nanoparticles or nanoplates. DETA plays an important role in the formation process of cobalt mesocrystal. The possible formation mechanism is proposed. The cobalt mesocrystals not only exhibit Co nanocrystals property (an enhanced coercive force being 260 Oe at 300 K), but also have bulk Co property (saturation magnetization being 168 emu·g-1). The synthesis method in large scale is facile and effective with high yield.
