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2018 Volume 34 Issue 11
2018, 34(11): 1943-1949
doi: 10.11862/CJIC.2018.250
Abstract:
Near-infrared nanometer probe (M507@SNP) is obtained by monomer self-assembly between silica precursor and triblock copolymer F108 and then doping hydrophobic near-infrared dye M507. The photophysical properties and cytotoxicity of M507@SNP are investigated. Furthermore, M507@SNP is used as a fluorescent nanoprobe for monitoring whole-body and sentinel lymph node of rodents with high signal-to-noise.
Near-infrared nanometer probe (M507@SNP) is obtained by monomer self-assembly between silica precursor and triblock copolymer F108 and then doping hydrophobic near-infrared dye M507. The photophysical properties and cytotoxicity of M507@SNP are investigated. Furthermore, M507@SNP is used as a fluorescent nanoprobe for monitoring whole-body and sentinel lymph node of rodents with high signal-to-noise.
2018, 34(11): 1966-1974
doi: 10.11862/CJIC.2018.258
Abstract:
The adsorption of CO2 in MIL-101(Cr)-NH2 and MIL-101(Cr)-ED (ED:ethylene diamine) obtained by amine-functionalized MIL-101(Cr) at 298 K were investigated by using experimental and molecular simulation method. The adsorption isotherms and the heats of adsorption of MIL-101(Cr), MIL-101(Cr)-NH2 and MIL-101(Cr)-ED were compared and the results showed that MIL-101(Cr)-NH2 obtained by pre-functionalization approach has higher CO2 adsorption capacity than MIL-101(Cr)-ED obtained by post-synthetic modification. Snapshots and radial density functions were further compared to analyze the adsorption sites of CO2 in amine-functionalized MIL-101(Cr) and it was found that adsorption first occurs in the microporous super tetrahedron at low pressures and then in the bigger pores with increasing pressure. The presence of amine groups in MIL-101(Cr)-NH2 increases the adsorption sites of CO2 which results in higher CO2 adsorption capacity. Similarly, the presence of ED molecules in MIL-101(Cr)-ED increases the CO2 adsorption sites, resulting in higher CO2 adsorption capacity. However, the adsorption strength of Cr to CO2 is weaken by ED molecules since they occupy the Cr adsorption sites. Furthermore, the adsorption sites of MIL-101(Cr)-ED are less than that of MIL-101(Cr)-NH2. Therefore, MIL-101(Cr)-ED has lower CO2 adsorption capacity than MIL-101(Cr)-NH2.
The adsorption of CO2 in MIL-101(Cr)-NH2 and MIL-101(Cr)-ED (ED:ethylene diamine) obtained by amine-functionalized MIL-101(Cr) at 298 K were investigated by using experimental and molecular simulation method. The adsorption isotherms and the heats of adsorption of MIL-101(Cr), MIL-101(Cr)-NH2 and MIL-101(Cr)-ED were compared and the results showed that MIL-101(Cr)-NH2 obtained by pre-functionalization approach has higher CO2 adsorption capacity than MIL-101(Cr)-ED obtained by post-synthetic modification. Snapshots and radial density functions were further compared to analyze the adsorption sites of CO2 in amine-functionalized MIL-101(Cr) and it was found that adsorption first occurs in the microporous super tetrahedron at low pressures and then in the bigger pores with increasing pressure. The presence of amine groups in MIL-101(Cr)-NH2 increases the adsorption sites of CO2 which results in higher CO2 adsorption capacity. Similarly, the presence of ED molecules in MIL-101(Cr)-ED increases the CO2 adsorption sites, resulting in higher CO2 adsorption capacity. However, the adsorption strength of Cr to CO2 is weaken by ED molecules since they occupy the Cr adsorption sites. Furthermore, the adsorption sites of MIL-101(Cr)-ED are less than that of MIL-101(Cr)-NH2. Therefore, MIL-101(Cr)-ED has lower CO2 adsorption capacity than MIL-101(Cr)-NH2.
2018, 34(11): 1975-1982
doi: 10.11862/CJIC.2018.229
Abstract:
NaY(WO4)2 microparticles with tetragonal scheelite structure and Er3+/Yb3+ co-doped NaY(WO4)2 phosphors were synthesized by traditional hydrothermal method. The crystal structure, morphology and up-conversion luminescence properties of the samples were discussed detailedly via XRD, SEM, TEM, HRTEM, particle size distribution and up-conversion luminescence spectrum. The results indicated that the pH values played an important role in the synthesis of pure phase NaY(WO4)2 microparticles with regular morphology. As pH value increased, the morphology of the samples could generate a transition from octahedrons, quasi-cubes to plate particles and a possible morphological formation mechanism of NaY(WO4)2 was proposed. Er3+/Yb3+ co-doped NaY(WO4)2 samples show strong green (2H11/2→4I15/2 (525 nm) and 4S3/2→4I15/2 (553 nm) of Er3+) and weak red (650~680 nm:4F9/2→4I15/2 of Er3+) up-conversion emission under 980 nm laser diode excitation, and the two-photon process was confirmed to be responsible for the green and red up-conversion emissions. Moreover, by adjusting the doping concentration of Yb3+ in NaY(WO4)2:Er3+, Yb3+ phosphors, the color-tunable and high-purity green were exhibited by the CIE color coordinates of NaY(WO4)2:Er3+, Yb3+ phosphors.
NaY(WO4)2 microparticles with tetragonal scheelite structure and Er3+/Yb3+ co-doped NaY(WO4)2 phosphors were synthesized by traditional hydrothermal method. The crystal structure, morphology and up-conversion luminescence properties of the samples were discussed detailedly via XRD, SEM, TEM, HRTEM, particle size distribution and up-conversion luminescence spectrum. The results indicated that the pH values played an important role in the synthesis of pure phase NaY(WO4)2 microparticles with regular morphology. As pH value increased, the morphology of the samples could generate a transition from octahedrons, quasi-cubes to plate particles and a possible morphological formation mechanism of NaY(WO4)2 was proposed. Er3+/Yb3+ co-doped NaY(WO4)2 samples show strong green (2H11/2→4I15/2 (525 nm) and 4S3/2→4I15/2 (553 nm) of Er3+) and weak red (650~680 nm:4F9/2→4I15/2 of Er3+) up-conversion emission under 980 nm laser diode excitation, and the two-photon process was confirmed to be responsible for the green and red up-conversion emissions. Moreover, by adjusting the doping concentration of Yb3+ in NaY(WO4)2:Er3+, Yb3+ phosphors, the color-tunable and high-purity green were exhibited by the CIE color coordinates of NaY(WO4)2:Er3+, Yb3+ phosphors.
2018, 34(11): 1983-1990
doi: 10.11862/CJIC.2018.224
Abstract:
The composite materials of conductive polymer@nickel and aluminum double metal hydroxide were prepared using the simple and mild hydrothermal conditions, constructing the nano-channels for high-speed transmission of electrons and electrolyte. The morphologies and microstructures of the composites were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results of electrochemical performance showed that the conductive polymer could provide some pseudocapacitance for the composite material, promote the rapid transfer of charge, and improve significantly the capacitive performance of CP@NiAl-LDH. The polypyrrole@LDH had the best performance of capacitance, the specific capacity could reach 3 010.3 F·g-1 at the current density of 1 A·g-1, and the specific capacitance remained 73.1% when the current density increased to 20 A·g-1, exhibiting excellent rate performance. Furthermore, it also displayed excellent cycling stability with a specific capacity retention rate of 88.8% after 10 000 times of charge-discharge cycles at the current density of 10 A·g-1. These were mainly ascribed to the synergetic enhancement effect among NiAl-LDH and conductive polymer.
The composite materials of conductive polymer@nickel and aluminum double metal hydroxide were prepared using the simple and mild hydrothermal conditions, constructing the nano-channels for high-speed transmission of electrons and electrolyte. The morphologies and microstructures of the composites were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results of electrochemical performance showed that the conductive polymer could provide some pseudocapacitance for the composite material, promote the rapid transfer of charge, and improve significantly the capacitive performance of CP@NiAl-LDH. The polypyrrole@LDH had the best performance of capacitance, the specific capacity could reach 3 010.3 F·g-1 at the current density of 1 A·g-1, and the specific capacitance remained 73.1% when the current density increased to 20 A·g-1, exhibiting excellent rate performance. Furthermore, it also displayed excellent cycling stability with a specific capacity retention rate of 88.8% after 10 000 times of charge-discharge cycles at the current density of 10 A·g-1. These were mainly ascribed to the synergetic enhancement effect among NiAl-LDH and conductive polymer.
High Specific Area Cerium Oxide: Synthesis and Effect on Catalytic Performance of Pt-Based Catalysts
2018, 34(11): 1991-1999
doi: 10.11862/CJIC.2018.247
Abstract:
A broom-like CeO2 with a specific surface area of 175 m2·g-1 and a pore size of 2~4 nm was synthesized by hydrothermal method. The Pt-CeO2/RGO catalyst was prepared by the microwave-assisted ethylene glycol reduction chloroplatinic acid method, and the effect of the addition of broom-like CeO2 on the electrocatalytic performance of Pt-based catalysts was investigated. The prepared CeO2 and catalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of catalysts was tested by electrochemical workstation. The results showed that the CeO2 in the catalyst remains in the form of a broom, and the Pt nanoparticles are evenly distributed on the surface of graphene carrier. When the mass ratio of RGO to CeO2(mRGO:mCeO2) is 1:2, the electrocatalytic performance of the Pt-CeO2/RGO catalyst with broom-like CeO2 is the best, the electrochemical active surface area was 102.83 m2·g-1, the peak current density of ethanol oxidation was 757.17 A·g-1, the steady-state current density of 1 000 s was 108.17 A·g-1, the charge transfer resistance of the catalytic oxidation reaction of ethanol is the smallest and the activation energy is the lowest.
A broom-like CeO2 with a specific surface area of 175 m2·g-1 and a pore size of 2~4 nm was synthesized by hydrothermal method. The Pt-CeO2/RGO catalyst was prepared by the microwave-assisted ethylene glycol reduction chloroplatinic acid method, and the effect of the addition of broom-like CeO2 on the electrocatalytic performance of Pt-based catalysts was investigated. The prepared CeO2 and catalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of catalysts was tested by electrochemical workstation. The results showed that the CeO2 in the catalyst remains in the form of a broom, and the Pt nanoparticles are evenly distributed on the surface of graphene carrier. When the mass ratio of RGO to CeO2(mRGO:mCeO2) is 1:2, the electrocatalytic performance of the Pt-CeO2/RGO catalyst with broom-like CeO2 is the best, the electrochemical active surface area was 102.83 m2·g-1, the peak current density of ethanol oxidation was 757.17 A·g-1, the steady-state current density of 1 000 s was 108.17 A·g-1, the charge transfer resistance of the catalytic oxidation reaction of ethanol is the smallest and the activation energy is the lowest.
2018, 34(11): 2000-2008
doi: 10.11862/CJIC.2018.252
Abstract:
The pastes containing quantum dot (QDs)/TiO2 were first synthesized, and then screen printing and doctor blading were employed for coating the pastes onto ITO/PET flexible substrates. The results show that doctor blading was universal and more effective to obtain high efficiency quantum dot sensitized solar cell (QDSCs). The assembled ZnCuInSe, CdSe and CdSeTe semi-flexible QDSCs obtained high conversion efficiencies of 2.83%, 2.46% and 1.99% respectively when brass-based counter electrodes (CEs) were used. Furthermore, surface chemical modification was first carried out on graphite paper (GP) to improve the hydrophilicity, then CuxS nanoparticles were grown on GP via successive ionic layer adsorption and reaction (SILAR). The as-prepared flexible CuxS/GP CEs exhibited satisfactory performance and the assembled fully flexible ZnCuInSe QDSCs obtained high efficiency of 2.13%.
The pastes containing quantum dot (QDs)/TiO2 were first synthesized, and then screen printing and doctor blading were employed for coating the pastes onto ITO/PET flexible substrates. The results show that doctor blading was universal and more effective to obtain high efficiency quantum dot sensitized solar cell (QDSCs). The assembled ZnCuInSe, CdSe and CdSeTe semi-flexible QDSCs obtained high conversion efficiencies of 2.83%, 2.46% and 1.99% respectively when brass-based counter electrodes (CEs) were used. Furthermore, surface chemical modification was first carried out on graphite paper (GP) to improve the hydrophilicity, then CuxS nanoparticles were grown on GP via successive ionic layer adsorption and reaction (SILAR). The as-prepared flexible CuxS/GP CEs exhibited satisfactory performance and the assembled fully flexible ZnCuInSe QDSCs obtained high efficiency of 2.13%.
2018, 34(11): 2009-2018
doi: 10.11862/CJIC.2018.262
Abstract:
Ag@AgBr/CNT/Ni thin films were prepared by composite electroplating. The surface morphology, phase structure, chemical composition and optical characteristics of the thin film were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), respectively. Its photocatalytic properties and stability were evaluated with rhodamine B(RhB) as a model compound under visible light. By measuring the electrochemical impedance spectroscopy (EIS) and adding active species trapping agents to the reaction system, the mechanism of photocatalytic degradation of the film was explored. The results show that the Ag@AgBr/CNT/Ni thin film prepared under the optimized conditions is composed of a small amount of carbon nanotubes (CNT) and AgBr crystals coated with nano-Ag particles, which have a significant surface plasmon resonance (SPR) effect. The thin film exhibits a maximum photocatalytic activity and a superior photocatalytic stability to decompose RhB. The photodegradation rate (92.7%) of the Ag@AgBr/CNT/Ni thin film under visible light irradiation 20 min is 1.32 times greater than that of Ag@AgBr/Ni thin film, and 21.6 times greater than that of P25 TiO2/ITO thin film. The photocatalytic activity kept mostly unchanged after five recycled experiments. The existence of CNT greatly increases the charge conductivity and the photocatalytic reduction property for dissolved oxygen of the Ag@AgBr/CNT/Ni thin film, which is the main reason for the improvement of the photocatalytic properties of the film. In addition, the photocatalytic reaction mechanism of the film for RhB under visible light irradiation was also discussed.
Ag@AgBr/CNT/Ni thin films were prepared by composite electroplating. The surface morphology, phase structure, chemical composition and optical characteristics of the thin film were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), respectively. Its photocatalytic properties and stability were evaluated with rhodamine B(RhB) as a model compound under visible light. By measuring the electrochemical impedance spectroscopy (EIS) and adding active species trapping agents to the reaction system, the mechanism of photocatalytic degradation of the film was explored. The results show that the Ag@AgBr/CNT/Ni thin film prepared under the optimized conditions is composed of a small amount of carbon nanotubes (CNT) and AgBr crystals coated with nano-Ag particles, which have a significant surface plasmon resonance (SPR) effect. The thin film exhibits a maximum photocatalytic activity and a superior photocatalytic stability to decompose RhB. The photodegradation rate (92.7%) of the Ag@AgBr/CNT/Ni thin film under visible light irradiation 20 min is 1.32 times greater than that of Ag@AgBr/Ni thin film, and 21.6 times greater than that of P25 TiO2/ITO thin film. The photocatalytic activity kept mostly unchanged after five recycled experiments. The existence of CNT greatly increases the charge conductivity and the photocatalytic reduction property for dissolved oxygen of the Ag@AgBr/CNT/Ni thin film, which is the main reason for the improvement of the photocatalytic properties of the film. In addition, the photocatalytic reaction mechanism of the film for RhB under visible light irradiation was also discussed.
2018, 34(11): 2019-2024
doi: 10.11862/CJIC.2018.264
Abstract:
Two-dimensional layered molybdenum sulfide supported on carbon nanofibers (MoS2/CNFs) were successfully obtained by electro-spinning and hydrothermal methods and showed excellent electrochemical properties. During the preparation of DSSCs, the film thickness of the electrode had a great influence on the performance of the DSSCs. Focuses on the effect of the film thickness of the counter electrode prepared by spraying method on the optical properties of the DSSCs and the optimum counter electrode film thickness was obtained. The experimental results show that the film thickness of the MoS2/CNFs composite counter electrode material was 8 μm, the photoelectric conversion efficiency of the battery reached a maximum value of 7.78%.
Two-dimensional layered molybdenum sulfide supported on carbon nanofibers (MoS2/CNFs) were successfully obtained by electro-spinning and hydrothermal methods and showed excellent electrochemical properties. During the preparation of DSSCs, the film thickness of the electrode had a great influence on the performance of the DSSCs. Focuses on the effect of the film thickness of the counter electrode prepared by spraying method on the optical properties of the DSSCs and the optimum counter electrode film thickness was obtained. The experimental results show that the film thickness of the MoS2/CNFs composite counter electrode material was 8 μm, the photoelectric conversion efficiency of the battery reached a maximum value of 7.78%.
2018, 34(11): 2025-2031
doi: 10.11862/CJIC.2018.240
Abstract:
Hierarchical sodalite (SOD) zeolite was synthesized by "steam-assisted conversion (SAC)" method using the as-synthesized polystyrene (PS) microspheres as templates. The factors affecting the formation of the hierarchical SOD were discussed in details. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, and mercury intrusion method. The results exhibited that the as-synthesized monolithic SOD zeolite consisted of sphere-like polycrystalline aggregates which were further composed of primary SOD nano-crystals with a size of 50~100 nm. An intercrystalline and intracrystalline mesoporous structure ranging from 2 to 50 nm along with a macropore with 50~300 nm resulted from the removal of PS microspheres were created in the as-prepared SOD samples.
Hierarchical sodalite (SOD) zeolite was synthesized by "steam-assisted conversion (SAC)" method using the as-synthesized polystyrene (PS) microspheres as templates. The factors affecting the formation of the hierarchical SOD were discussed in details. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, and mercury intrusion method. The results exhibited that the as-synthesized monolithic SOD zeolite consisted of sphere-like polycrystalline aggregates which were further composed of primary SOD nano-crystals with a size of 50~100 nm. An intercrystalline and intracrystalline mesoporous structure ranging from 2 to 50 nm along with a macropore with 50~300 nm resulted from the removal of PS microspheres were created in the as-prepared SOD samples.
2018, 34(11): 2032-2040
doi: 10.11862/CJIC.2018.263
Abstract:
Tungsten nitride-Tungsten/nitrogen doped ordered mesoporous carbon (WN/W-NOMC), as a non-precious-metal cathode catalyst for oxygen reduction reaction (ORR), was successfully synthesized through a soft-template method.The amount of nitrogen was adjusted by urea, and when the content of nitrogen was 7%(w/w), the obtained composite had highly ordered mesoporous structure, and its specific surface area reached to 835 m2·g-1.Transmission electron microscope (TEM) shows that the catalytic particles were uniform supported on NOMC.ORR test was conducted in O2-staturated 0.1 mol·L-1 KOH solution, the oneset potential is 0.87 V (vs RHE) and the limiting current density is 4.49 mA·cm-2.The transfer number of electron was 3.4, which was close to commercial 20%(w/w) Pt/C (3.8), indicated that WN-NOMC exhibited an approximate 4e- transfer pathway during the ORR process.Though the catalytic activity is less than Pt/C, the excellent methanol tolerance and long-time electrochemical stability make WN-W/NOMC to be a potential electrode catalyst for ORR.
Tungsten nitride-Tungsten/nitrogen doped ordered mesoporous carbon (WN/W-NOMC), as a non-precious-metal cathode catalyst for oxygen reduction reaction (ORR), was successfully synthesized through a soft-template method.The amount of nitrogen was adjusted by urea, and when the content of nitrogen was 7%(w/w), the obtained composite had highly ordered mesoporous structure, and its specific surface area reached to 835 m2·g-1.Transmission electron microscope (TEM) shows that the catalytic particles were uniform supported on NOMC.ORR test was conducted in O2-staturated 0.1 mol·L-1 KOH solution, the oneset potential is 0.87 V (vs RHE) and the limiting current density is 4.49 mA·cm-2.The transfer number of electron was 3.4, which was close to commercial 20%(w/w) Pt/C (3.8), indicated that WN-NOMC exhibited an approximate 4e- transfer pathway during the ORR process.Though the catalytic activity is less than Pt/C, the excellent methanol tolerance and long-time electrochemical stability make WN-W/NOMC to be a potential electrode catalyst for ORR.
2018, 34(11): 1950-1965
doi: 10.11862/CJIC.2018.245
Abstract:
In order to efficiently degrade organic pollutants in water, a new photocatalyst Sm2FeSbO7 was prepared by a solid-state reaction method for the first time. The construction and photocatalytic property of Sm2FeSbO7 had been characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscope and UV-visible spectrometer. Sm2FeSbO7 crystallized with a pyrochlore-type structure, a cubic crystal system and a space group Fd3m. The lattice parameter a of Sm2FeSbO7 was 1.035 434 nm. The band gap of Sm2FeSbO7 was estimated to be 2.46 eV. The photocatalytic degradation of indigo carmine was accomplished under visible light irradiation with Sm2FeSbO7 as a catalyst compared with nitrogen-doped TiO2. The results indicated that Sm2FeSbO7 displayed higher photocatalytic activity compared with nitrogen-doped TiO2 for the photocatalytic degradation of indigo carmine under visible light irradiation. The reduction of the total organic carbon, the gradual formation of inorganic products, SO42- and NO3-, and the evolution of CO2 revealed the continuous mineralization of indigo carmine during the photocatalytic process. Some intermediate products which came from the photocatalytic degradation of indigo carmine were detected, such as o-nitrobenzoic acid and o-nitrobenzaldehyde, and a possible photocatalytic degradation path of indigo carmine was acquired.
In order to efficiently degrade organic pollutants in water, a new photocatalyst Sm2FeSbO7 was prepared by a solid-state reaction method for the first time. The construction and photocatalytic property of Sm2FeSbO7 had been characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscope and UV-visible spectrometer. Sm2FeSbO7 crystallized with a pyrochlore-type structure, a cubic crystal system and a space group Fd3m. The lattice parameter a of Sm2FeSbO7 was 1.035 434 nm. The band gap of Sm2FeSbO7 was estimated to be 2.46 eV. The photocatalytic degradation of indigo carmine was accomplished under visible light irradiation with Sm2FeSbO7 as a catalyst compared with nitrogen-doped TiO2. The results indicated that Sm2FeSbO7 displayed higher photocatalytic activity compared with nitrogen-doped TiO2 for the photocatalytic degradation of indigo carmine under visible light irradiation. The reduction of the total organic carbon, the gradual formation of inorganic products, SO42- and NO3-, and the evolution of CO2 revealed the continuous mineralization of indigo carmine during the photocatalytic process. Some intermediate products which came from the photocatalytic degradation of indigo carmine were detected, such as o-nitrobenzoic acid and o-nitrobenzaldehyde, and a possible photocatalytic degradation path of indigo carmine was acquired.
2018, 34(11): 2041-2048
doi: 10.11862/CJIC.2018.249
Abstract:
A Pt-free counter electrode (CE) composed of La2Mo2O7 (La2O3-2MoO2) was successfully synthesized via the simple pyrolysis of lanthanum acetate (C6H9O6La·xH2O) and hexaammonium heptamolybdate tetrahydrate ((NH4)6Mo7O24·4H2O) in a high-temperature solid-state reaction.Also, La2Mo2O7 and multiwall carbon nanotubes (MWCNTs) are combined using two methods.La2Mo2O7/MWCNTs was prepared by spray-coating La2Mo2O7 over the surface of MWCNTs, and La2Mo2O7@MWCNTs was synthesized by doping La2Mo2O7 into MWCNTs.The two types of composite materials were further used as Pt-free catalytic material in CEs in dye sensitized solar cells (DSSCs).The morphology and microstructure of La2Mo2O7/MWCNTs and La2Mo2O7@MWCNTs were determined using scanning electron microscopy and X-ray diffraction.The electrochemical performance of the La2Mo2O7/MWCNTs and La2Mo2O7@MWCNTs composite catalysts for CEs was determined using photocurrent-voltage measurements, cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization in encapsulation of DSSCs batteries.The experimental results show that power conversion efficiencies of 6.09% and 4.84% were obtained for La2Mo2O7/MWCNTs and La2Mo2O7@MWCNTs, respectively, as CEs toward the reduction of I3-/I- ions, and these values are superior to those of MWCNTs (3.94%) and the La2Mo2O7 (0.87%) electrode under the same conditions.The enhanced electrode performance was attributed to the relatively larger surface area and higher conductivity of the La2Mo2O7/MWCNTs composite catalysts.
A Pt-free counter electrode (CE) composed of La2Mo2O7 (La2O3-2MoO2) was successfully synthesized via the simple pyrolysis of lanthanum acetate (C6H9O6La·xH2O) and hexaammonium heptamolybdate tetrahydrate ((NH4)6Mo7O24·4H2O) in a high-temperature solid-state reaction.Also, La2Mo2O7 and multiwall carbon nanotubes (MWCNTs) are combined using two methods.La2Mo2O7/MWCNTs was prepared by spray-coating La2Mo2O7 over the surface of MWCNTs, and La2Mo2O7@MWCNTs was synthesized by doping La2Mo2O7 into MWCNTs.The two types of composite materials were further used as Pt-free catalytic material in CEs in dye sensitized solar cells (DSSCs).The morphology and microstructure of La2Mo2O7/MWCNTs and La2Mo2O7@MWCNTs were determined using scanning electron microscopy and X-ray diffraction.The electrochemical performance of the La2Mo2O7/MWCNTs and La2Mo2O7@MWCNTs composite catalysts for CEs was determined using photocurrent-voltage measurements, cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization in encapsulation of DSSCs batteries.The experimental results show that power conversion efficiencies of 6.09% and 4.84% were obtained for La2Mo2O7/MWCNTs and La2Mo2O7@MWCNTs, respectively, as CEs toward the reduction of I3-/I- ions, and these values are superior to those of MWCNTs (3.94%) and the La2Mo2O7 (0.87%) electrode under the same conditions.The enhanced electrode performance was attributed to the relatively larger surface area and higher conductivity of the La2Mo2O7/MWCNTs composite catalysts.
2018, 34(11): 2049-2056
doi: 10.11862/CJIC.2018.257
Abstract:
Two novel complexes, [Cu2(bbix)(dpa)2(C2H5OH)2]n (1) and {[Cd(bbix)0.5(dpa)]·0.5H2O}n (2) (H2dpa=diphenic acid, bbix=1, 4-bis(benzimidazol-1-ylmethyl)-benzene), were synthesized and structurally characterized under solvothermal conditions.Both 1 and 2 exhibit two-dimensional (2D) architecture.Complex 1 has 63 wave-like layer consisting of Cu-dpa helical chains in which the Cu(Ⅱ) ions as 3-connecting nodes.While the layer structure of 2 consists of one-dimensional chains containing alternated 4-membered and 8-membered rings.Furthermore, the solid-state properties of thermal stability for all crystalline materials and the fluorescence property of 2 at room temperature have been investigated.
Two novel complexes, [Cu2(bbix)(dpa)2(C2H5OH)2]n (1) and {[Cd(bbix)0.5(dpa)]·0.5H2O}n (2) (H2dpa=diphenic acid, bbix=1, 4-bis(benzimidazol-1-ylmethyl)-benzene), were synthesized and structurally characterized under solvothermal conditions.Both 1 and 2 exhibit two-dimensional (2D) architecture.Complex 1 has 63 wave-like layer consisting of Cu-dpa helical chains in which the Cu(Ⅱ) ions as 3-connecting nodes.While the layer structure of 2 consists of one-dimensional chains containing alternated 4-membered and 8-membered rings.Furthermore, the solid-state properties of thermal stability for all crystalline materials and the fluorescence property of 2 at room temperature have been investigated.
2018, 34(11): 2057-2062
doi: 10.11862/CJIC.2018.253
Abstract:
Two complexes[Ni(L)(OAc)] (1) and[Co(L)2]Cl·4CH3OH (2) (HL=2-aceto-3-methylpyrazine N-(4-fluorophenyl)thiosemicarbazone) have been synthesized and structurally determined by single-crystal X-ray diffraction, elemental analysis and IR spectroscopy.X-ray diffraction analysis results show that the Ni(Ⅱ) ion in complex 1 with a distorted square planar geometry is surrounded by one anionic TSC ligand with NNS donor set and one monodentate acetate.By contrast, Co(Ⅲ) ion coordinates with two tridentate TSC ligands, and thus possessing a distorted octahedron coordination geometry.Moreover, the fluorescence spectra indicate that the interactions of complexes 1 and 2 with DNA are stronger than that of the ligand HL.
Two complexes[Ni(L)(OAc)] (1) and[Co(L)2]Cl·4CH3OH (2) (HL=2-aceto-3-methylpyrazine N-(4-fluorophenyl)thiosemicarbazone) have been synthesized and structurally determined by single-crystal X-ray diffraction, elemental analysis and IR spectroscopy.X-ray diffraction analysis results show that the Ni(Ⅱ) ion in complex 1 with a distorted square planar geometry is surrounded by one anionic TSC ligand with NNS donor set and one monodentate acetate.By contrast, Co(Ⅲ) ion coordinates with two tridentate TSC ligands, and thus possessing a distorted octahedron coordination geometry.Moreover, the fluorescence spectra indicate that the interactions of complexes 1 and 2 with DNA are stronger than that of the ligand HL.
2018, 34(11): 2063-2072
doi: 10.11862/CJIC.2018.233
Abstract:
Three iron(Ⅱ) tetrahedral cages 1~3 with solid state spin-crossover properties were rational constructed.Single crystal X-ray diffraction analysis confirmed the edge-capped capsule, which were assembled from six imidazole Schiff-base ligands and four iron(Ⅱ) ions.The metal centers occupy the vertices and each linker situates at the edges of the tetrahedron.The inner cavities of these cages are surrounded by imidazole groups, while the periphery is decorated by substituted phenyl rings.One of the counter anions is encapsulated at the central cavities and shows strong anion binding interactions with the cages.Interestingly, the iron(Ⅱ) cages in solution can change their spin states from low-spin (LS) to high-spin (HS) upon addition of halide, since tremendous change of solution color and absorption intensity of characteristic broad absorption MLCT bands when addition of halide (Cl- and Br-) to the CH3CN solution of the cages.
Three iron(Ⅱ) tetrahedral cages 1~3 with solid state spin-crossover properties were rational constructed.Single crystal X-ray diffraction analysis confirmed the edge-capped capsule, which were assembled from six imidazole Schiff-base ligands and four iron(Ⅱ) ions.The metal centers occupy the vertices and each linker situates at the edges of the tetrahedron.The inner cavities of these cages are surrounded by imidazole groups, while the periphery is decorated by substituted phenyl rings.One of the counter anions is encapsulated at the central cavities and shows strong anion binding interactions with the cages.Interestingly, the iron(Ⅱ) cages in solution can change their spin states from low-spin (LS) to high-spin (HS) upon addition of halide, since tremendous change of solution color and absorption intensity of characteristic broad absorption MLCT bands when addition of halide (Cl- and Br-) to the CH3CN solution of the cages.
2018, 34(11): 2073-2080
doi: 10.11862/CJIC.2018.244
Abstract:
The surface of silicon nitride (Si3N4) powder was efficiently hydroxylated via application of nitric acid to improve dispersibility in aqueous media.Hydroxylated powder results in more stable colloidal dispersion in aqueous media compared to native powder.Results of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy show that hydroxyl group content of Si3N4 powder significantly increased with hydroxyl modification.This is helpful in preventing Si3N4 powder from aggregating in aqueous media.In addition, thermogravimetric analysis indicates that hydroxyl group content of hydroxylated Si3N4 powder was 68.8% higher than that of native powder.Furthermore, surface hydrophilicity of Si3N4 powder is enhanced with hydroxyl modification, and powder dispersibility is improved with an increase in hydroxyl content.
The surface of silicon nitride (Si3N4) powder was efficiently hydroxylated via application of nitric acid to improve dispersibility in aqueous media.Hydroxylated powder results in more stable colloidal dispersion in aqueous media compared to native powder.Results of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy show that hydroxyl group content of Si3N4 powder significantly increased with hydroxyl modification.This is helpful in preventing Si3N4 powder from aggregating in aqueous media.In addition, thermogravimetric analysis indicates that hydroxyl group content of hydroxylated Si3N4 powder was 68.8% higher than that of native powder.Furthermore, surface hydrophilicity of Si3N4 powder is enhanced with hydroxyl modification, and powder dispersibility is improved with an increase in hydroxyl content.
2018, 34(11): 2081-2087
doi: 10.11862/CJIC.2018.254
Abstract:
A Mn(Ⅱ) coordination polymer, {[Mn(DPA)(4, 4'-bipy)]·H2O}n (1) was prepared with 3, 3'-thiodipropionic acid (DPA), 4, 4'-bipyridine (4, 4'-bipy) and Mn(NO3)2·4H2O by hydrothermal method, and a Cu(Ⅱ) coordination polymer, {[Cu(DPA)(bpp)(H2O)]·H2O}n (2) was hydrothermal synthesized by using 3, 3'-thiodipropionic acid (DPA), 1, 3-bis(4-pyridyl)propane (bpp) and Cu(NO3)2·3H2O. The coordination polymers were characterized by elemental analysis, thermal analysis, IR, XRD and X-ray single crystal diffraction. Complexes 1 and 2 have two-dimensional layer structures, Furthermore, there are hydrogen bonds and π-π stacking interactions contributing three-dimensional supramolecular structures of 1 and 2, respectively.
A Mn(Ⅱ) coordination polymer, {[Mn(DPA)(4, 4'-bipy)]·H2O}n (1) was prepared with 3, 3'-thiodipropionic acid (DPA), 4, 4'-bipyridine (4, 4'-bipy) and Mn(NO3)2·4H2O by hydrothermal method, and a Cu(Ⅱ) coordination polymer, {[Cu(DPA)(bpp)(H2O)]·H2O}n (2) was hydrothermal synthesized by using 3, 3'-thiodipropionic acid (DPA), 1, 3-bis(4-pyridyl)propane (bpp) and Cu(NO3)2·3H2O. The coordination polymers were characterized by elemental analysis, thermal analysis, IR, XRD and X-ray single crystal diffraction. Complexes 1 and 2 have two-dimensional layer structures, Furthermore, there are hydrogen bonds and π-π stacking interactions contributing three-dimensional supramolecular structures of 1 and 2, respectively.
2018, 34(11): 2088-2096
doi: 10.11862/CJIC.2018.260
Abstract:
Ti-containing SiO2 nanotubes (TiSNTs) were firstly synthesized via a sol-gel and co-polycondensation method. After that, a family of Mn doped TiSNTs (Mn/TiSNTs) catalysts with various Mn loading were prepared via the co-precipitation method. When Si/Ti molar ratio was more than 5, a worm-like tubular morphology was clearly observed. The NH3-TPD (NH3-temperature programmed desorption) results show that the Ti doping into the skeleton of the silica nanotubes greatly enhanced the acidic sites of the catalyst and promoted the adsorption and NH3-SCR (selective catalytic reduction) activation on the surface of the catalyst. Meanwhile, the results of H2-TPR (H2-temperature programmed reduction) also show that Ti doping enhanced the redox ability of the catalyst and the capacity of oxygen storage. Moreover, the doped Mn species was beneficial for reducing the reaction temperature. The results of SCR of NOx with NH3 show the catalyst with Si/Ti molar ratios of 10 (Mn/Ti(10)SNT) exhibited significant catalytic activity, and the NO conversion rate remained over 90% in the reactive temperature range of 135 to 325℃.
Ti-containing SiO2 nanotubes (TiSNTs) were firstly synthesized via a sol-gel and co-polycondensation method. After that, a family of Mn doped TiSNTs (Mn/TiSNTs) catalysts with various Mn loading were prepared via the co-precipitation method. When Si/Ti molar ratio was more than 5, a worm-like tubular morphology was clearly observed. The NH3-TPD (NH3-temperature programmed desorption) results show that the Ti doping into the skeleton of the silica nanotubes greatly enhanced the acidic sites of the catalyst and promoted the adsorption and NH3-SCR (selective catalytic reduction) activation on the surface of the catalyst. Meanwhile, the results of H2-TPR (H2-temperature programmed reduction) also show that Ti doping enhanced the redox ability of the catalyst and the capacity of oxygen storage. Moreover, the doped Mn species was beneficial for reducing the reaction temperature. The results of SCR of NOx with NH3 show the catalyst with Si/Ti molar ratios of 10 (Mn/Ti(10)SNT) exhibited significant catalytic activity, and the NO conversion rate remained over 90% in the reactive temperature range of 135 to 325℃.
2018, 34(11): 2097-2107
doi: 10.11862/CJIC.2018.256
Abstract:
Two 2-amino-3-hydroxy-pyridine Schiff base binuclear Ni(Ⅱ) and Zn(Ⅱ) complexes, [Ni(L1)(DMF)]2 (1) (H2L1=4-hydroxy-3-((3-hydroxy-pyridin-2-ylimino)-methyl)-chromen-2-one) and[Zn(L2)(H2O)]2·2DMF (2) (H2L2=2-((3, 5-dibromo-2-hydroxy-benzylidene)-amino)-pyridin-3-ol) have been synthesized and characterized by elemental analyses, IR, UV-Vis, emission spectra and X-ray crystallography. X-ray crystallography analyses showed that complexes 1 and 2 all possess the binuclear structures, consisting of two metal ions, two ligand units and two coordinated solvent molecules, in which the difference is that complex 2 contains two solvent molecules. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and the center Ni(Ⅱ) and Zn(Ⅱ) are all five-coordinated slightly distorted square pyramid geometry by four O atoms and one imine N atoms. Complex 1 (or 2) links some other molecules into an infinite 3D network supramolecular structure via intermolecular hydrogen bond, C-H…π or π…π stacking interactions. And the fluorescent properties of H2L1, H2L2 and their corresponding Ni(Ⅱ) and Zn(Ⅱ) complexes have been discussed. The ligands H2L1 and H2L2 exhibit blue emission with the maximum emission wavelength λem=457 and 473 nm, and complexes 1 and 2 show green emission with λem=543 and 538 nm.
Two 2-amino-3-hydroxy-pyridine Schiff base binuclear Ni(Ⅱ) and Zn(Ⅱ) complexes, [Ni(L1)(DMF)]2 (1) (H2L1=4-hydroxy-3-((3-hydroxy-pyridin-2-ylimino)-methyl)-chromen-2-one) and[Zn(L2)(H2O)]2·2DMF (2) (H2L2=2-((3, 5-dibromo-2-hydroxy-benzylidene)-amino)-pyridin-3-ol) have been synthesized and characterized by elemental analyses, IR, UV-Vis, emission spectra and X-ray crystallography. X-ray crystallography analyses showed that complexes 1 and 2 all possess the binuclear structures, consisting of two metal ions, two ligand units and two coordinated solvent molecules, in which the difference is that complex 2 contains two solvent molecules. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and the center Ni(Ⅱ) and Zn(Ⅱ) are all five-coordinated slightly distorted square pyramid geometry by four O atoms and one imine N atoms. Complex 1 (or 2) links some other molecules into an infinite 3D network supramolecular structure via intermolecular hydrogen bond, C-H…π or π…π stacking interactions. And the fluorescent properties of H2L1, H2L2 and their corresponding Ni(Ⅱ) and Zn(Ⅱ) complexes have been discussed. The ligands H2L1 and H2L2 exhibit blue emission with the maximum emission wavelength λem=457 and 473 nm, and complexes 1 and 2 show green emission with λem=543 and 538 nm.
2018, 34(11): 2108-2114
doi: 10.11862/CJIC.2018.248
Abstract:
Two new complexes based on 3, 5-dinitrosalicylic acid (H2dns) and 1, 10-phenanthroline (phen), namely[La2(dns)2(Hdns)2(phen)4] (1) and[La4(dns)6(phen)6] (2) have been synthesized and characterized by IR, elemental analyses, thermogravimetric analyses and X-ray diffraction technique. Single-crystal X-ray diffraction analyses revealed that two complexes all crystallize in the triclinic system and space group P1. For complexes 1, H2dns ligands adopt tridentate and didentate coordination modes to link La(Ⅲ) ions into dinuclear structure. However H2dns ligands adopt tridentate coordination mode to link La(Ⅲ) ions into tetranuclear structure. TG and fluorescence analysis show the thermal stability of 2 is higher than that of 1, and 1 and 2 have same maximum emission band of the fluorescence at 467 nm.
Two new complexes based on 3, 5-dinitrosalicylic acid (H2dns) and 1, 10-phenanthroline (phen), namely[La2(dns)2(Hdns)2(phen)4] (1) and[La4(dns)6(phen)6] (2) have been synthesized and characterized by IR, elemental analyses, thermogravimetric analyses and X-ray diffraction technique. Single-crystal X-ray diffraction analyses revealed that two complexes all crystallize in the triclinic system and space group P1. For complexes 1, H2dns ligands adopt tridentate and didentate coordination modes to link La(Ⅲ) ions into dinuclear structure. However H2dns ligands adopt tridentate coordination mode to link La(Ⅲ) ions into tetranuclear structure. TG and fluorescence analysis show the thermal stability of 2 is higher than that of 1, and 1 and 2 have same maximum emission band of the fluorescence at 467 nm.
2018, 34(11): 2115-2126
doi: 10.11862/CJIC.2018.255
Abstract:
Both organic cetyltrimethyl ammonium bromide (CTAB) and inorganic NaBr are served as the bromine source, the thylakoid-like La doped BiOBr photocatalysts were synthesized via a hydrothermal process. The obtained samples were first characterized by X-ray diffraction (XRD), N2 physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. Then, the effects of photo-oxidation and reduction properties of BiOBr with La doping were investigated by DFT calculation. The photo-oxidation and reduction activity of the pure and La doped BiOBr samples were evaluated by photo-catalytic degradation of acid orange Ⅱ, ammonia nitrogen and methylene blue reduction under visible light irradiation. The results showed that it could inhibit growth of BiOBr crystals and promote the stacking crystals when La doped. More importantly, the oxidation performances of BiOBr were promoted, where the reduction performances were inhibited in large part by La doping.
Both organic cetyltrimethyl ammonium bromide (CTAB) and inorganic NaBr are served as the bromine source, the thylakoid-like La doped BiOBr photocatalysts were synthesized via a hydrothermal process. The obtained samples were first characterized by X-ray diffraction (XRD), N2 physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. Then, the effects of photo-oxidation and reduction properties of BiOBr with La doping were investigated by DFT calculation. The photo-oxidation and reduction activity of the pure and La doped BiOBr samples were evaluated by photo-catalytic degradation of acid orange Ⅱ, ammonia nitrogen and methylene blue reduction under visible light irradiation. The results showed that it could inhibit growth of BiOBr crystals and promote the stacking crystals when La doped. More importantly, the oxidation performances of BiOBr were promoted, where the reduction performances were inhibited in large part by La doping.
