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2017 Volume 33 Issue 7
2017, 33(7): 1097-1118
doi: 10.11862/CJIC.2017.152
Abstract:
Due to the simple preparation process, low cost and excellent photoelectric conversion efficiency, organic-inorganic hybrid perovskite solar cell has become a research hotspot in the field of photovoltaic technology.The perovskite optical absorption material has the advantages of high extinction coefficient, high carrier mobility, long carrier diffusion distance, long carrier lifetime, adjustable band gap, and a variety of preparation methods.In recent years, the efficiency of perovskite solar cells increased from the initial 3.8% in 2009 to the current 22.1%.In order to obtain long-term stable and high efficient perovskite solar cell at present, main research ideas have the following aspects including new structure design for solar cell, morphology design for functional layer, interface modification between each functional layer, selection of hole transport material and selection of counter electrode.Based on the review of the research progress of the perovskite solar cell, we first introduced the structure and working principle of the perovskite solar cell in this paper.Besides, the preparation process and various modification methods of electron transport layer were emphatically summarized.The electron transport layer plays a role in the transport of electrons and blocking holes in the structure of the perovskite solar cell.The energy level of electron transport layer can be controlled by doping technology to obtain better photoelectric conversion efficiency.The introduction of modification material on the electron transport layer can improve the morphology of the perovskite optical absorption layer, which can enhance the transmission and collection efficiency of the charge to improve the photoelectric conversion efficiency of the device.Afterwards, the synthesis optimization methods of the perovskite films were also discussed.The morphology and crystallinity of perovskite films can directly affect the optical trapping efficiency and short circuit current density.Therefore, high quality perovskite thin films were obtained by means of synthesis optimization, solvent engineering and annealing engineering.Moreover, we analyzed the reasons for the poor stability of perovskite solar cells, and then put forward the strategy to improve the stability of the solar cell.Finally, the commercial prospects of perovskite solar cells are forecasted.
Due to the simple preparation process, low cost and excellent photoelectric conversion efficiency, organic-inorganic hybrid perovskite solar cell has become a research hotspot in the field of photovoltaic technology.The perovskite optical absorption material has the advantages of high extinction coefficient, high carrier mobility, long carrier diffusion distance, long carrier lifetime, adjustable band gap, and a variety of preparation methods.In recent years, the efficiency of perovskite solar cells increased from the initial 3.8% in 2009 to the current 22.1%.In order to obtain long-term stable and high efficient perovskite solar cell at present, main research ideas have the following aspects including new structure design for solar cell, morphology design for functional layer, interface modification between each functional layer, selection of hole transport material and selection of counter electrode.Based on the review of the research progress of the perovskite solar cell, we first introduced the structure and working principle of the perovskite solar cell in this paper.Besides, the preparation process and various modification methods of electron transport layer were emphatically summarized.The electron transport layer plays a role in the transport of electrons and blocking holes in the structure of the perovskite solar cell.The energy level of electron transport layer can be controlled by doping technology to obtain better photoelectric conversion efficiency.The introduction of modification material on the electron transport layer can improve the morphology of the perovskite optical absorption layer, which can enhance the transmission and collection efficiency of the charge to improve the photoelectric conversion efficiency of the device.Afterwards, the synthesis optimization methods of the perovskite films were also discussed.The morphology and crystallinity of perovskite films can directly affect the optical trapping efficiency and short circuit current density.Therefore, high quality perovskite thin films were obtained by means of synthesis optimization, solvent engineering and annealing engineering.Moreover, we analyzed the reasons for the poor stability of perovskite solar cells, and then put forward the strategy to improve the stability of the solar cell.Finally, the commercial prospects of perovskite solar cells are forecasted.
2017, 33(7): 1132-1138
doi: 10.11862/CJIC.2017.170
Abstract:
Highly efficient TiO2 photocatalysts co-modified by reduced graphene oxide (rGO) as electron-transfer mediator and Ni (Ⅱ) as interfacial catalytic active-sites (referred to as Ni (Ⅱ)/TiO2-rGO) were synthesized via a two-step process including the initial hydrothermal method of rGO on the TiO2 surface and the following low-temperature impregnation method of Ni (Ⅱ) on the rGO.Photocatalytic experimental results indicated that all resulted Ni (Ⅱ)/TiO2-rGO photocatalysts exhibited obviously high H2-production performance.The highest H2-production rate of the resultant Ni (Ⅱ)/TiO2-rGO (0.1 mol·L-1) reached 77.0 μmol·h-1, while this value was higher than that of the TiO2(16.4 μmol·h-1) and TiO2-rGO (28.0 μmol·h-1) by a factor of 4.70 and 2.75, respectively.On the basis of the experimental results, a synergistic effect mechanism of rGO and Ni (Ⅱ) bi-cocatalysts was proposed to account for its enhanced H2-production performance, namely, rGO functions as an electron-transfer mediator to rapidly capture and transfer the photogenerated electron from TiO2 surface, while the Ni (Ⅱ) cocatalyst serves as an effectively active site for the following reduction.
Highly efficient TiO2 photocatalysts co-modified by reduced graphene oxide (rGO) as electron-transfer mediator and Ni (Ⅱ) as interfacial catalytic active-sites (referred to as Ni (Ⅱ)/TiO2-rGO) were synthesized via a two-step process including the initial hydrothermal method of rGO on the TiO2 surface and the following low-temperature impregnation method of Ni (Ⅱ) on the rGO.Photocatalytic experimental results indicated that all resulted Ni (Ⅱ)/TiO2-rGO photocatalysts exhibited obviously high H2-production performance.The highest H2-production rate of the resultant Ni (Ⅱ)/TiO2-rGO (0.1 mol·L-1) reached 77.0 μmol·h-1, while this value was higher than that of the TiO2(16.4 μmol·h-1) and TiO2-rGO (28.0 μmol·h-1) by a factor of 4.70 and 2.75, respectively.On the basis of the experimental results, a synergistic effect mechanism of rGO and Ni (Ⅱ) bi-cocatalysts was proposed to account for its enhanced H2-production performance, namely, rGO functions as an electron-transfer mediator to rapidly capture and transfer the photogenerated electron from TiO2 surface, while the Ni (Ⅱ) cocatalyst serves as an effectively active site for the following reduction.
2017, 33(7): 1147-1152
doi: 10.11862/CJIC.2017.156
Abstract:
The Na-doped Li1-xNaxMn2O4(x=0, 0.01, 0.03, 0.05) was successfully synthesized by a sol-gel method.X-ray diffraction showed Na is successfully doped into LiMn2O4 structure.SEM images showed the material is a uniform particle with 100~300 nm particle size.Galvanostatic charge/discharge results show the discharge capacity retention of Li0.97Na0.03Mn2O4 after 100 cycles at 2C was increased from 51.2% to 84.1% compared with that of undoped LiMn2O4.The results of cyclic voltammetry indicate that Na doping reduced the polarization and increased the diffusion coefficient of lithium ions.When the current density is increased to 10C, the doped sample still has a discharge capacity at 79.0 mAh·g-1, which is higher than that of the undoped sample (52.1 mAh·g-1).Na doping can stabilize the material structure and improve the diffusion coefficient of lithium ions, thereby improving the electrochemical properties of LiMn2O4, is a viable modification method.
The Na-doped Li1-xNaxMn2O4(x=0, 0.01, 0.03, 0.05) was successfully synthesized by a sol-gel method.X-ray diffraction showed Na is successfully doped into LiMn2O4 structure.SEM images showed the material is a uniform particle with 100~300 nm particle size.Galvanostatic charge/discharge results show the discharge capacity retention of Li0.97Na0.03Mn2O4 after 100 cycles at 2C was increased from 51.2% to 84.1% compared with that of undoped LiMn2O4.The results of cyclic voltammetry indicate that Na doping reduced the polarization and increased the diffusion coefficient of lithium ions.When the current density is increased to 10C, the doped sample still has a discharge capacity at 79.0 mAh·g-1, which is higher than that of the undoped sample (52.1 mAh·g-1).Na doping can stabilize the material structure and improve the diffusion coefficient of lithium ions, thereby improving the electrochemical properties of LiMn2O4, is a viable modification method.
2017, 33(7): 1153-1160
doi: 10.11862/CJIC.2017.141
Abstract:
The catalytic performance of catalyst supported on the Al2O3-MgO was unstable due to the loss of aluminum ions caused by the excessive NaOH.In this study, a stable catalyst Na2O/Al2O3-MgO was synthesized using the ammonia as precipitator to generate co-precipitate of Mg-Al which it subsequently underwent impregnation with Na2CO3, aging process and calcination.In addition, the structure and morphology of the catalyst were characterized through XRD, SEM, SEM-EDS, TG-DSC, and N2 adsorption-desorption, and the catalytic activity was evaluated by the methyl esterification rate of malania oleifera oil.The results showed that catalyst precursors with the hydrotalcite-like structure could be obtained by co-precipitation and impregnation method, which the decomposition temperature of it was in the range of 200~500℃ and there were Na-Al as well as Na-Mg-Al oxides in the catalyst after high temperature calcination.The preparation condition of Na2O/Al2O3-MgO catalyst with high activity covered nMg/nAl as 3:1~1:3, the aging time as 12 hours, calcination temperature as 550℃ and calcination time as 5 hours.The verification experiment of catalyst prepared with nMg/nAl as 1:1 was conducted and the result revealed that the catalyst was a mesoporous catalyst with specific surface area of 30 m2·g-1 and the average pore size of 8.8 nm.Moreover, the catalyst processed high activity in the methyl esterification rate of malania oleifera oil and the conversion rate was up to 96.4%.
The catalytic performance of catalyst supported on the Al2O3-MgO was unstable due to the loss of aluminum ions caused by the excessive NaOH.In this study, a stable catalyst Na2O/Al2O3-MgO was synthesized using the ammonia as precipitator to generate co-precipitate of Mg-Al which it subsequently underwent impregnation with Na2CO3, aging process and calcination.In addition, the structure and morphology of the catalyst were characterized through XRD, SEM, SEM-EDS, TG-DSC, and N2 adsorption-desorption, and the catalytic activity was evaluated by the methyl esterification rate of malania oleifera oil.The results showed that catalyst precursors with the hydrotalcite-like structure could be obtained by co-precipitation and impregnation method, which the decomposition temperature of it was in the range of 200~500℃ and there were Na-Al as well as Na-Mg-Al oxides in the catalyst after high temperature calcination.The preparation condition of Na2O/Al2O3-MgO catalyst with high activity covered nMg/nAl as 3:1~1:3, the aging time as 12 hours, calcination temperature as 550℃ and calcination time as 5 hours.The verification experiment of catalyst prepared with nMg/nAl as 1:1 was conducted and the result revealed that the catalyst was a mesoporous catalyst with specific surface area of 30 m2·g-1 and the average pore size of 8.8 nm.Moreover, the catalyst processed high activity in the methyl esterification rate of malania oleifera oil and the conversion rate was up to 96.4%.
2017, 33(7): 1161-1171
doi: 10.11862/CJIC.2017.139
Abstract:
Hierarchical nanoflower-ring structure Bi2O3/(BiO)2CO3(BO/BCO) composite was successfully synthesized by the temperature-programmed hydrothermal treatment.X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis/DRS), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and N2 adsorption-desorption tests were employed to characterize the crystalline phase, chemical composition, optical absorption properties, morphology and surface physicochemical properties of as-synthetized material.The results showed that the crystalline phase of (BiO)2CO3 was tetragonal phase, and the crystalline phase of Bi2O3 was the monoclinic phase in as-composite Bi2O3/(BiO)2CO3 which had both as-crystal structures.Moreover, with the introduction of OH- and reaction time increasing in synthesis process, the intensity of characteristics diffraction peak of (BiO)2CO3 was gradually decreased, meanwhile, that of Bi2O3 was gradually increased, showing that the proportions of Bi2O3 were increased in the sample with reaction time increased.The results of UV-Vis/DRS analysis showed that the absorption edge of as-synthetized composite BO/BCO had shift compared to pure Bi2O3 and pure (BiO)2CO3, and the absorption was effectively increased in the visible light region with the introduction of Bi2O3.At the same time, (BiO)2CO3 nanolayer was changed to the hierarchical nanoflower-ring structure BO/BCO-0.5 composite, and the formation of special morphology leads to narrowed band gap and change the reflection and scattering of photoelectrons, which were conducive to the absorption efficiency of light and transfering of photogenerated charges.In addition, the photocatalytic activities of as-composites BO/BCO were studied by degradation photocatalytic experiments of RhB as the model molecule under different light irradiation, the cycle experiment and the capture experiment.The results of photocatalytic activity experiment showed that the activity of BO/BCO-0.5 was significantly higher than that of other systems (Bi2O3 and P25), and the photocatalytic activity of BO/BCO-0.5 was kept even after three cycles.Meanwhile, according to the capture experimental results, the possible photocatalytic reaction mechanism of BO/BCO composite was speculated.
Hierarchical nanoflower-ring structure Bi2O3/(BiO)2CO3(BO/BCO) composite was successfully synthesized by the temperature-programmed hydrothermal treatment.X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis/DRS), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and N2 adsorption-desorption tests were employed to characterize the crystalline phase, chemical composition, optical absorption properties, morphology and surface physicochemical properties of as-synthetized material.The results showed that the crystalline phase of (BiO)2CO3 was tetragonal phase, and the crystalline phase of Bi2O3 was the monoclinic phase in as-composite Bi2O3/(BiO)2CO3 which had both as-crystal structures.Moreover, with the introduction of OH- and reaction time increasing in synthesis process, the intensity of characteristics diffraction peak of (BiO)2CO3 was gradually decreased, meanwhile, that of Bi2O3 was gradually increased, showing that the proportions of Bi2O3 were increased in the sample with reaction time increased.The results of UV-Vis/DRS analysis showed that the absorption edge of as-synthetized composite BO/BCO had shift compared to pure Bi2O3 and pure (BiO)2CO3, and the absorption was effectively increased in the visible light region with the introduction of Bi2O3.At the same time, (BiO)2CO3 nanolayer was changed to the hierarchical nanoflower-ring structure BO/BCO-0.5 composite, and the formation of special morphology leads to narrowed band gap and change the reflection and scattering of photoelectrons, which were conducive to the absorption efficiency of light and transfering of photogenerated charges.In addition, the photocatalytic activities of as-composites BO/BCO were studied by degradation photocatalytic experiments of RhB as the model molecule under different light irradiation, the cycle experiment and the capture experiment.The results of photocatalytic activity experiment showed that the activity of BO/BCO-0.5 was significantly higher than that of other systems (Bi2O3 and P25), and the photocatalytic activity of BO/BCO-0.5 was kept even after three cycles.Meanwhile, according to the capture experimental results, the possible photocatalytic reaction mechanism of BO/BCO composite was speculated.
2017, 33(7): 1172-1180
doi: 10.11862/CJIC.2017.137
Abstract:
Three new complexes, {[M (TFPT)(DPP)]·H2O}n(M=Cd (1), Ni (2)), {[Cd (TFPT)(BTB)0.5]·2H2O}n(3) were synthesized by using transition metal salts, 3, 4, 5, 6-tetrafluorophthalate (TFPT), 1, 3-di (4-pyridyl)-propane (DPP) and 1, 4-bis (1, 2, 4-triazol-1-yl) butane (BTB) by hydrothermal method.The crystal structures were determined by single crystal X-ray diffraction.Complexes 1 and 2 have similar one-dimensional chain structure.The configuration of center metal ion is distorted octahedral of[MO4N2].Complex 3 is two-dimensional structure.The configuration of center metal ion is distorted octahedral of[CdO5N].Complexes 1 and 3 have ligand-based fluorescence emissions, which are corresponding to π*-π transition of the ligand at 424 nm and 442 nm, respectively.Complex 2 has very weak fluorescence emission at 356 nm.It is interesting to note that different metal cations have different effects on fluorescence of complexes 1 and 3.They would be regarded as a sensor for Fe3+ ions in aqueous solutions via a fluorescence quenching mechanism.
Three new complexes, {[M (TFPT)(DPP)]·H2O}n(M=Cd (1), Ni (2)), {[Cd (TFPT)(BTB)0.5]·2H2O}n(3) were synthesized by using transition metal salts, 3, 4, 5, 6-tetrafluorophthalate (TFPT), 1, 3-di (4-pyridyl)-propane (DPP) and 1, 4-bis (1, 2, 4-triazol-1-yl) butane (BTB) by hydrothermal method.The crystal structures were determined by single crystal X-ray diffraction.Complexes 1 and 2 have similar one-dimensional chain structure.The configuration of center metal ion is distorted octahedral of[MO4N2].Complex 3 is two-dimensional structure.The configuration of center metal ion is distorted octahedral of[CdO5N].Complexes 1 and 3 have ligand-based fluorescence emissions, which are corresponding to π*-π transition of the ligand at 424 nm and 442 nm, respectively.Complex 2 has very weak fluorescence emission at 356 nm.It is interesting to note that different metal cations have different effects on fluorescence of complexes 1 and 3.They would be regarded as a sensor for Fe3+ ions in aqueous solutions via a fluorescence quenching mechanism.
2017, 33(7): 1181-1186
doi: 10.11862/CJIC.2017.146
Abstract:
The visible light active ternary composite AgI/AgCl/h-BN was synthesized via water-soluble KCl crystal temple and ion-exchange process using h-BN nanosheets as the catalyst support.The structure and morphology of as-prepared samples were characterized by XRD, FT-IR, SEM and TEM.The absorption properties of the samples were analyzed by UV-Vis DRS.The result of photocatalytic degradation rate of RhB can reach 93% after 24 min illumination under visible light, indicating that the higher photocatalytic activity and stability of AgI/AgCl/h-BN than bulk AgCl, AgCl cubes, AgI/AgCl nanocashews and that reported in the literature.And the degradation rate of RhB kept almost unchanged after 4 cycles, which indicated AgI/AgCl/h-BN photocatalyst excellent stability.Furthermore, the proposed mechanisms for the enhanced photocatalytic and stability were investigated by photoelectron chemical measurements, radical trapping experiments and ESR analysis.
The visible light active ternary composite AgI/AgCl/h-BN was synthesized via water-soluble KCl crystal temple and ion-exchange process using h-BN nanosheets as the catalyst support.The structure and morphology of as-prepared samples were characterized by XRD, FT-IR, SEM and TEM.The absorption properties of the samples were analyzed by UV-Vis DRS.The result of photocatalytic degradation rate of RhB can reach 93% after 24 min illumination under visible light, indicating that the higher photocatalytic activity and stability of AgI/AgCl/h-BN than bulk AgCl, AgCl cubes, AgI/AgCl nanocashews and that reported in the literature.And the degradation rate of RhB kept almost unchanged after 4 cycles, which indicated AgI/AgCl/h-BN photocatalyst excellent stability.Furthermore, the proposed mechanisms for the enhanced photocatalytic and stability were investigated by photoelectron chemical measurements, radical trapping experiments and ESR analysis.
2017, 33(7): 1187-1195
doi: 10.11862/CJIC.2017.143
Abstract:
The geometric structures, electronic configurations, bonding characteristic, and thermodynamic properties of low valence iron complexes Fe (CO)5-x(PR3)x(x=1~3, R=H, F, Me) were studied using the density functional theory (DFT) method.The results show that the geometric framework of Fe (CO)5-x(PR3)x is not aberrant but maintain the distorted trigonal bipyramidal structure after the introduction of phosphorus ligand.Natural bond orbital (NBO) analysis show that there is charge transfer between the phosphorus ligand to the carbonyl iron fragment.Moreover, the covalent interaction between Fe and CO is enhanced.The phosphorus ligand dissociation energy is lower than the first carbonyl dissociation energy from the most stable structure Fe (CO)5-x(PR3)x.This indicates that the reactivity of Fe (CO)5-x(PR3)x is largely greater than Fe (CO)5.
The geometric structures, electronic configurations, bonding characteristic, and thermodynamic properties of low valence iron complexes Fe (CO)5-x(PR3)x(x=1~3, R=H, F, Me) were studied using the density functional theory (DFT) method.The results show that the geometric framework of Fe (CO)5-x(PR3)x is not aberrant but maintain the distorted trigonal bipyramidal structure after the introduction of phosphorus ligand.Natural bond orbital (NBO) analysis show that there is charge transfer between the phosphorus ligand to the carbonyl iron fragment.Moreover, the covalent interaction between Fe and CO is enhanced.The phosphorus ligand dissociation energy is lower than the first carbonyl dissociation energy from the most stable structure Fe (CO)5-x(PR3)x.This indicates that the reactivity of Fe (CO)5-x(PR3)x is largely greater than Fe (CO)5.
2017, 33(7): 1196-1204
doi: 10.11862/CJIC.2017.140
Abstract:
BiPO4, Ag3PO4 and BiPO4/Ag3PO4 heterostructure photocatalysts were synthesized by one-step hydro-thermal method.X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) techniques were used to characterize morphology, crystal structure, and absorption spectrum.The SEM results showed that the BiPO4/Ag3PO4 sample was in blocky structure and BiPO4 distributed on the surface of Ag3PO4.The XRD of BiPO4/Ag3PO4 sample displayed monoclinic and cubic crystal structure.The UV-Vis DRS spectra results indicated that the BiPO4/Ag3PO4 sample displayed obviously red shifts compared to BiPO4 and the light absorption range broaden to 571 nm.Moreover, the photocatalytic activity was evaluated by photodegradation of methyl orange (MO) and gatifloxacin solution under simulated sunlight irradiation.BiPO4/Ag3PO4 exhibits higher degradation and mineralized activities and the better stability on degradation of methyl orange and gatifloxacin than the single BiPO4 and Ag3PO4.Moreover, the test of active radical showed that the h+ was the main active radical in the degradation process, ·O2- was weaker.The enhanced photocatalytic activity and stability of BiPO4/Ag3PO4 was mainly attributes to the formation of p-n heterojunction interface in BiPO4/Ag3PO4 which facilitated the transfer and separation of photogenerated electron-hole pairs confirmed by the results of transient photocurrent response and electrochemical impedance spectroscopy measurement.Based on the above results, the photocatalytic mechanism for organics degradation over BiPO4/Ag3PO4 was proposed.
BiPO4, Ag3PO4 and BiPO4/Ag3PO4 heterostructure photocatalysts were synthesized by one-step hydro-thermal method.X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) techniques were used to characterize morphology, crystal structure, and absorption spectrum.The SEM results showed that the BiPO4/Ag3PO4 sample was in blocky structure and BiPO4 distributed on the surface of Ag3PO4.The XRD of BiPO4/Ag3PO4 sample displayed monoclinic and cubic crystal structure.The UV-Vis DRS spectra results indicated that the BiPO4/Ag3PO4 sample displayed obviously red shifts compared to BiPO4 and the light absorption range broaden to 571 nm.Moreover, the photocatalytic activity was evaluated by photodegradation of methyl orange (MO) and gatifloxacin solution under simulated sunlight irradiation.BiPO4/Ag3PO4 exhibits higher degradation and mineralized activities and the better stability on degradation of methyl orange and gatifloxacin than the single BiPO4 and Ag3PO4.Moreover, the test of active radical showed that the h+ was the main active radical in the degradation process, ·O2- was weaker.The enhanced photocatalytic activity and stability of BiPO4/Ag3PO4 was mainly attributes to the formation of p-n heterojunction interface in BiPO4/Ag3PO4 which facilitated the transfer and separation of photogenerated electron-hole pairs confirmed by the results of transient photocurrent response and electrochemical impedance spectroscopy measurement.Based on the above results, the photocatalytic mechanism for organics degradation over BiPO4/Ag3PO4 was proposed.
2017, 33(7): 1205-1216
doi: 10.11862/CJIC.2017.134
Abstract:
Niobate bismuth nanoparticles doped with La and Zn had been prepared by chemical co-precipitation method, and its structure and photocatalytic property were characterized by means of modern analytical techniques.The results illustrated that the doped BiNbO4 samples presented an excellent photocatalytic activity on RhB in visible light irradiation, and their photocatalytic efficiency influenced by various factors, 0.15 g of Bi0.96La0.04NbO4 had the best photocatalytic effect on 50 mL of RhB solution with 5 mg·L-1 and 4 of pH.Especially, it had a stable photocatalytic performance and still retained the photocatalytic activity beyond 95% after five cycling test.The study on photocatalysis mechanism indicated that the electron holes play a significant role in the degradation process of RhB under visible light irradiation.
Niobate bismuth nanoparticles doped with La and Zn had been prepared by chemical co-precipitation method, and its structure and photocatalytic property were characterized by means of modern analytical techniques.The results illustrated that the doped BiNbO4 samples presented an excellent photocatalytic activity on RhB in visible light irradiation, and their photocatalytic efficiency influenced by various factors, 0.15 g of Bi0.96La0.04NbO4 had the best photocatalytic effect on 50 mL of RhB solution with 5 mg·L-1 and 4 of pH.Especially, it had a stable photocatalytic performance and still retained the photocatalytic activity beyond 95% after five cycling test.The study on photocatalysis mechanism indicated that the electron holes play a significant role in the degradation process of RhB under visible light irradiation.
2017, 33(7): 1217-1222
doi: 10.11862/CJIC.2017.136
Abstract:
Probe molecules of Eu (MAA)3Phen, Eu (Sal)3Phen and Eu (CA)3Phen were prepared by using europium oxide (Eu2O3), methacrylate (MAA), salicylic acid (HSal), cinnamic acid (HCA) and phenanthroline (Phen).A series of temperature sensitive paints (TSPs) were obtained by the polymerization of different probe molecules, methyl methacrylate (MMA) and the initiator of benzoyl peroxide (BPO).The structure, morphology, luminescence property of probe molecules and the temperature quenching property of TSPs were characterized by infrared spectrometer, fluorescence spectrometer and scanning electron microscopy.The effect of different ligands on the luminescence property of probe molecules and the temperature quenching property of TSPs were studied.It is indicated that the fluorescence intensity of Eu (MAA)3Phen is obviously higher than that of Eu (Sal)3Phen or Eu (CA)3Phen, and the temperature quenching properties of the three TSPs are good.The temperature sensitivity of Eu (MAA)3Phen/PMMA and Eu (CA)3Phen/PMMA is higher in 55~65℃.However, the temperature sensitivity of Eu (Sal)3Phen/PMMA is higher in 35~45℃.That is to say, different TSPs can be used in different temperature ranges.
Probe molecules of Eu (MAA)3Phen, Eu (Sal)3Phen and Eu (CA)3Phen were prepared by using europium oxide (Eu2O3), methacrylate (MAA), salicylic acid (HSal), cinnamic acid (HCA) and phenanthroline (Phen).A series of temperature sensitive paints (TSPs) were obtained by the polymerization of different probe molecules, methyl methacrylate (MMA) and the initiator of benzoyl peroxide (BPO).The structure, morphology, luminescence property of probe molecules and the temperature quenching property of TSPs were characterized by infrared spectrometer, fluorescence spectrometer and scanning electron microscopy.The effect of different ligands on the luminescence property of probe molecules and the temperature quenching property of TSPs were studied.It is indicated that the fluorescence intensity of Eu (MAA)3Phen is obviously higher than that of Eu (Sal)3Phen or Eu (CA)3Phen, and the temperature quenching properties of the three TSPs are good.The temperature sensitivity of Eu (MAA)3Phen/PMMA and Eu (CA)3Phen/PMMA is higher in 55~65℃.However, the temperature sensitivity of Eu (Sal)3Phen/PMMA is higher in 35~45℃.That is to say, different TSPs can be used in different temperature ranges.
2017, 33(7): 1223-1230
doi: 10.11862/CJIC.2017.148
Abstract:
The Fe element doped CuS/RGO (Fe-CuS/RGO) was fabricated via a facile one-step solvothermal method, which displayed outstanding photocatalytic activity for methylene blue (MB) degradation.The composition and structure of the prepared composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, photoluminescence (PL) spectra, scanning electron microscopy (SEM), Transmission electron microscope (TEM) and UV-Vis optical absorption spectroscopy.The results showed that pristine CuS, CuS/RGO and Fe-CuS/RGO exhibited photocatalytic activity for the photodegradation of MB with degradation efficiency of 41.2%, 81.5% and 90.6%, respectively, in 140 min under mercury lamp irradiation, indicating that Fe-CuS/RGO could be acknowledged as a promising photocatalyst for the removal of organic contaminants.The enhanced photocatalytic activity was ascribed to that Fe element could be acted as an interfacial charge transfer channel between CuS and RGO to thus inhibit the recombination of photogenerated electron-holes pairs.
The Fe element doped CuS/RGO (Fe-CuS/RGO) was fabricated via a facile one-step solvothermal method, which displayed outstanding photocatalytic activity for methylene blue (MB) degradation.The composition and structure of the prepared composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, photoluminescence (PL) spectra, scanning electron microscopy (SEM), Transmission electron microscope (TEM) and UV-Vis optical absorption spectroscopy.The results showed that pristine CuS, CuS/RGO and Fe-CuS/RGO exhibited photocatalytic activity for the photodegradation of MB with degradation efficiency of 41.2%, 81.5% and 90.6%, respectively, in 140 min under mercury lamp irradiation, indicating that Fe-CuS/RGO could be acknowledged as a promising photocatalyst for the removal of organic contaminants.The enhanced photocatalytic activity was ascribed to that Fe element could be acted as an interfacial charge transfer channel between CuS and RGO to thus inhibit the recombination of photogenerated electron-holes pairs.
2017, 33(7): 1231-1235
doi: 10.11862/CJIC.2017.167
Abstract:
Copper/graphene composite materials were fabricated by hydrothermal method, and its structure and morphology were characterized by XRD, FTIR, SEM and TEM, the catalytic performance of this composite toward methylene blue was investigated at hydrogen peroxide solution.The results shown that the copper particles size were small and uniform distribution loading graphene sheets in the composite material, which exhibits good catalytic activity for the decolorization of methylene blue, the 0.18 g·L-1 composite catalyst with in 300 min on the decolorization rate of methylene blue can reach 90.7%, after 5 cycles on the catalytic efficiency of methylene blue test is still more than 88.0%.
Copper/graphene composite materials were fabricated by hydrothermal method, and its structure and morphology were characterized by XRD, FTIR, SEM and TEM, the catalytic performance of this composite toward methylene blue was investigated at hydrogen peroxide solution.The results shown that the copper particles size were small and uniform distribution loading graphene sheets in the composite material, which exhibits good catalytic activity for the decolorization of methylene blue, the 0.18 g·L-1 composite catalyst with in 300 min on the decolorization rate of methylene blue can reach 90.7%, after 5 cycles on the catalytic efficiency of methylene blue test is still more than 88.0%.
2017, 33(7): 1236-1242
doi: 10.11862/CJIC.2017.173
Abstract:
Lithium-rich layered oxide materials 0.6Li[Li1/3Mn2/3]O2·0.4LiNi5/12Mn5/12Co1/6O2(named as LNMCO) have been prepared by spray-drying method and followed by high temperature annealed and surface coated with ZrO2.The TEM results show that the ZrO2 layer with nano size particles is located on the surface of the particles.The initial coulombic efficiencies and discharge capacities of the 0.6Li[Li1/3Mn2/3]O2·0.4LiNi5/12Mn5/12Co1/6O2 lithium-rich layered oxide material are largely improved by ZrO2 coating, and the value is 87.2%, 279.3 mAh·g-1, compared to 75.1%, 224.1 mAh·g-1, respectively, for the bare sample at the room temperature and at a current density of 20 mA·g-1 in the voltage range of 2.0 to 4.8 V when the content of ZrO2 is 1.5%.After 100 cycles, the 1.5% ZrO2-coated sample shows a high discharge capacity of 248.3 mAh·g-1 with a capacity retention of 88.9%, while the bare LNMCO presents a lower discharge capacity of 195.9 mAh·g-1 with a capacity retention of 87.4%.
Lithium-rich layered oxide materials 0.6Li[Li1/3Mn2/3]O2·0.4LiNi5/12Mn5/12Co1/6O2(named as LNMCO) have been prepared by spray-drying method and followed by high temperature annealed and surface coated with ZrO2.The TEM results show that the ZrO2 layer with nano size particles is located on the surface of the particles.The initial coulombic efficiencies and discharge capacities of the 0.6Li[Li1/3Mn2/3]O2·0.4LiNi5/12Mn5/12Co1/6O2 lithium-rich layered oxide material are largely improved by ZrO2 coating, and the value is 87.2%, 279.3 mAh·g-1, compared to 75.1%, 224.1 mAh·g-1, respectively, for the bare sample at the room temperature and at a current density of 20 mA·g-1 in the voltage range of 2.0 to 4.8 V when the content of ZrO2 is 1.5%.After 100 cycles, the 1.5% ZrO2-coated sample shows a high discharge capacity of 248.3 mAh·g-1 with a capacity retention of 88.9%, while the bare LNMCO presents a lower discharge capacity of 195.9 mAh·g-1 with a capacity retention of 87.4%.
2017, 33(7): 1243-1248
doi: 10.11862/CJIC.2017.127
Abstract:
A simple and efficient two-steps one-pot synthetic methodology for the preparation of Fe (C5H4-CH2-Trp-OMe)2(FcL) is described, and FcL was fully characterized by NMR spectroscopic techniques, mass spectrometry (HRMS) and IR.The crystal structure of FcL was determined by X-ray single crystal structure analysis.The cyclic voltammetric behavior of FcL showed one pair of well-defined and stable redox waves in potential range of 0.0~0.9 V at GC electrode, which attributed to the Fc/Fc+ redox process.Electrochemical investigations of FcL have demonstrated that addition of Zn2+ and Cu2+ results in large shifts of respective Fc/Fc+ redox couple to more positive potentials, 342 and 335 mV, respectively, and this suggests that FcL has good ability in recognizing of the vital Zn2+ and Cu2+.
A simple and efficient two-steps one-pot synthetic methodology for the preparation of Fe (C5H4-CH2-Trp-OMe)2(FcL) is described, and FcL was fully characterized by NMR spectroscopic techniques, mass spectrometry (HRMS) and IR.The crystal structure of FcL was determined by X-ray single crystal structure analysis.The cyclic voltammetric behavior of FcL showed one pair of well-defined and stable redox waves in potential range of 0.0~0.9 V at GC electrode, which attributed to the Fc/Fc+ redox process.Electrochemical investigations of FcL have demonstrated that addition of Zn2+ and Cu2+ results in large shifts of respective Fc/Fc+ redox couple to more positive potentials, 342 and 335 mV, respectively, and this suggests that FcL has good ability in recognizing of the vital Zn2+ and Cu2+.
2017, 33(7): 1266-1272
doi: 10.11862/CJIC.2017.162
Abstract:
Two zinc/cadmium-based coordination polymers (CPs), [Zn (FDC)(DMF)2]n(1) and{(Me2NH2)2[Cd2(FDC)3(H2O)2]·4H2O}n(2)(H2FDC=2, 5-furandicarboxylic acid, DMF=N, N-dimethyl formamide) have been prepared based on 2, 5-furandicarboxylate under the same reaction conditions (130℃ and DMF) and were structurally characterized by elemental analysis, IR, TGA, powder X-ray diffraction and single-crystal X-ray diffraction.Complex 1 performs a 1D chain structure, where the chains are further connected into 2D layer structure by hydrogen bonds, whereas 2 shows 2D (4, 4) network and is unstable in air.The results of thermal analysis indicate that 1 is stable up to 300℃ after the DMF molecules are removed, but 2 is unstable after the aqua ligands, cations and solvent molecules are removed.Moreover, the luminescent properties of 1 and 2 were detected at room temperature under the excitations of 303 nm and 350 nm, respectively.Both of 1 and 2 emit the intensely blue characteristic luminescence at room temperature (λmax=406 and 470 nm), with lifetimes of up to 76.2 and 138.1 ns, respectively.CCDC:1489352, 1; 1527106, 2.
Two zinc/cadmium-based coordination polymers (CPs), [Zn (FDC)(DMF)2]n(1) and{(Me2NH2)2[Cd2(FDC)3(H2O)2]·4H2O}n(2)(H2FDC=2, 5-furandicarboxylic acid, DMF=N, N-dimethyl formamide) have been prepared based on 2, 5-furandicarboxylate under the same reaction conditions (130℃ and DMF) and were structurally characterized by elemental analysis, IR, TGA, powder X-ray diffraction and single-crystal X-ray diffraction.Complex 1 performs a 1D chain structure, where the chains are further connected into 2D layer structure by hydrogen bonds, whereas 2 shows 2D (4, 4) network and is unstable in air.The results of thermal analysis indicate that 1 is stable up to 300℃ after the DMF molecules are removed, but 2 is unstable after the aqua ligands, cations and solvent molecules are removed.Moreover, the luminescent properties of 1 and 2 were detected at room temperature under the excitations of 303 nm and 350 nm, respectively.Both of 1 and 2 emit the intensely blue characteristic luminescence at room temperature (λmax=406 and 470 nm), with lifetimes of up to 76.2 and 138.1 ns, respectively.CCDC:1489352, 1; 1527106, 2.
