以V_2O_5,AgNO_3和Y(NO_3)_3×6H_2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag_3VO_4和Y_2O3_/Ag_3VO_4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗...以V_2O_5,AgNO_3和Y(NO_3)_3×6H_2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag_3VO_4和Y_2O3_/Ag_3VO_4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗丹明B(Rh B)的性能.结果表明,所得Y_2O_3/Ag_3VO_4复合催化剂吸收边相对纯相Ag_3VO_4发生红移,禁带宽度减小至1.83 e V,电子-空穴对复合几率降低,对Rh B有较好的可见光催化活性和稳定性,可见光照射15 min后,0.08 g 3%Y2O_3/Ag_3VO_4催化200 m L 8 mg/L Rh B溶液的降解率达94.2%.展开更多
Over the past few years,the emission of organic pollutants into the environment has increased tremendously.Therefore,various photocatalysts have been developed for the degradation of organic pollutants.In this study,a...Over the past few years,the emission of organic pollutants into the environment has increased tremendously.Therefore,various photocatalysts have been developed for the degradation of organic pollutants.In this study,a step-scheme BiVO4/Ag3VO4 composite was synthesized via a hydrothermal and chemical deposition process for the degradation of methylene blue.The composite showed strong redox ability under visible light.The 40%BiVO4/Ag3VO4 composite showed excellent photocatalytic degradation properties with a Kapp of 0.05588 min^–1,which is 22.76 and 1.76 times higher than those of BiVO4(0.00247 min^–1)and Ag3VO4(0.03167 min^–1),respectively.The composite showed a stable performance and could retain 90%of its photocatalytic activity even after four cycles.The improved catalytic performance of the composite as compared to BiVO4 and Ag3VO4 can be attributed to its novel step-scheme mechanism,which facilitated the separation of the photogenerated charges and increased their lifetime.The photoluminescence measurement results and transient photocurrent response revealed that the composite showed efficient extraction of charge carriers.展开更多
Due to the high capacity,moderate voltage platform,and stable structure,Li3VO4(LVO) has attracted close attention as feasible anode material for lithium-ion capacitor.However,the intrinsic low electronic conductivity ...Due to the high capacity,moderate voltage platform,and stable structure,Li3VO4(LVO) has attracted close attention as feasible anode material for lithium-ion capacitor.However,the intrinsic low electronic conductivity and sluggish kinetics of the Li+ insertion process severely impede its practical application in lithium-ion capacitors(LICs).Herein,a carbon-coated Li3VO4(LVO/C) hierarchical structure was prepared by a facial one-step solid-state method.The synthesized LVO/C composite delivers an impressive capacity of 435 mAh/g at 0.07 A/g,remarkable rate capability,and nearly 100% capacity retention after 500 cycles at 0.5 A/g.The superior electrochemical properties of LVO/C composite materials are attributed to the improved conductivity of electron and stable carbon/LVO composite structures.Besides,the LIC device based on activated carbon(AC) cathode and optimal LVO/C as anode reveals a maximum energy density of 110 Wh/kg and long-term cycle life.These results provide a potential way for assembling the advanced hybrid lithium-ion capacitors.展开更多
Developing high-performance anode materials is crucial for the advancement of sodium-ion capacitors with high-energy density and large power density.Bimetallic oxides exhibit a high specific capacity due to their syne...Developing high-performance anode materials is crucial for the advancement of sodium-ion capacitors with high-energy density and large power density.Bimetallic oxides exhibit a high specific capacity due to their synergistic effects in electrochemical processes.However,challenges such as poor electrical conductivity,slow ion transport,and volume expansion severely limit their development.In this study,Co_(2)VO_(4)@C-1.5 was synthesized through a straightforward method involving solvent-heating and carbonization via calcination.The synergistic effect of Co and V,mitigation of volume expansion by the carbon-coated layer,enhancement of pseudocapacitive behavior and improved electrical conductivity of Co_(2)VO_(4)@C-1.5 contribute to its superior electrochemical performance.The specific capacity of Co_(2)VO_(4)@C-1.5 remained steady at 288.8 and 171.7 mAh g^(-1)after 100 and 500 cycles at 100 and 1000 mA g^(-1),respectively.Density functional theory(DFT)calculations show a notable reduction in the energy barrier of Co_(2)VO_(4)@C-1.5.Furthermore,the assembled sodium-ion capacitor Co_(2)VO_(4)@C-1.5//AC demonstrates high-energy density(108.5 Wh kg^(-1)at 99.8 W kg^(-1)),remarkable power density(38.2 Wh kg^(-1)at 12,000 W kg^(-1)),and longcycle stability(capacity retention of 80.6%after 6000 cycles).The design and optimization of the carbon-coated structure provide valuable insights for the development of bimetallic oxide materials in sodium-ion capacitors(SICs).展开更多
A pseudocapacitance dominated anode material assembled from Li_(3)VO_(4)nanocrystals encapsulated in the interlayers of N-doped graphene has been developed via a facile 2D nanospace confined strategy for lithium ion c...A pseudocapacitance dominated anode material assembled from Li_(3)VO_(4)nanocrystals encapsulated in the interlayers of N-doped graphene has been developed via a facile 2D nanospace confined strategy for lithium ion capacitors(LICs).In this contribution,the N-doped graphene synthesized by a faicle solid state reaction using C_(3)N_(4)nanosheets as template and glucose as carbon source provides sufficient 2D nanospace for the confined and homogeneous growth of Li_(3)VO_(4)at the nanoscale,and simultaneously efficiently anchors each nanobuilding block inside the interlayers,thus realizing the utilizaiton of full potential of active components.The so-formed 3D hybrids not only ensure intimate electronic coupling between active materials and N-doped graphene,but also realize robust structure integrity.Owing to these unique advantages,the resulting hybrids show pseudocapacitance dominated lithium storage behaviors with capacitive contributions of over 90%at both low and high current rates.The LVO@C@NG delivers reversible capacities of 206 mAh/g at 10 A/g,capacity retention of 92.7%after 1000 cycles at 2 A/g,and a high energy density of 113.6 Wh/kg at 231.8 W/kg for LICs.展开更多
文摘以V_2O_5,AgNO_3和Y(NO_3)_3×6H_2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag_3VO_4和Y_2O3_/Ag_3VO_4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗丹明B(Rh B)的性能.结果表明,所得Y_2O_3/Ag_3VO_4复合催化剂吸收边相对纯相Ag_3VO_4发生红移,禁带宽度减小至1.83 e V,电子-空穴对复合几率降低,对Rh B有较好的可见光催化活性和稳定性,可见光照射15 min后,0.08 g 3%Y2O_3/Ag_3VO_4催化200 m L 8 mg/L Rh B溶液的降解率达94.2%.
文摘Over the past few years,the emission of organic pollutants into the environment has increased tremendously.Therefore,various photocatalysts have been developed for the degradation of organic pollutants.In this study,a step-scheme BiVO4/Ag3VO4 composite was synthesized via a hydrothermal and chemical deposition process for the degradation of methylene blue.The composite showed strong redox ability under visible light.The 40%BiVO4/Ag3VO4 composite showed excellent photocatalytic degradation properties with a Kapp of 0.05588 min^–1,which is 22.76 and 1.76 times higher than those of BiVO4(0.00247 min^–1)and Ag3VO4(0.03167 min^–1),respectively.The composite showed a stable performance and could retain 90%of its photocatalytic activity even after four cycles.The improved catalytic performance of the composite as compared to BiVO4 and Ag3VO4 can be attributed to its novel step-scheme mechanism,which facilitated the separation of the photogenerated charges and increased their lifetime.The photoluminescence measurement results and transient photocurrent response revealed that the composite showed efficient extraction of charge carriers.
基金funded by the National Natural Science Foundation of China(Nos.51677182 and 51822706)the DNL Cooperation Fund(No.DNL201915)+1 种基金the Beijing Municipal Science and Technology Commission(No.Z181100000118006)the Beijing Nova Program(No.Z171100001117073)。
文摘Due to the high capacity,moderate voltage platform,and stable structure,Li3VO4(LVO) has attracted close attention as feasible anode material for lithium-ion capacitor.However,the intrinsic low electronic conductivity and sluggish kinetics of the Li+ insertion process severely impede its practical application in lithium-ion capacitors(LICs).Herein,a carbon-coated Li3VO4(LVO/C) hierarchical structure was prepared by a facial one-step solid-state method.The synthesized LVO/C composite delivers an impressive capacity of 435 mAh/g at 0.07 A/g,remarkable rate capability,and nearly 100% capacity retention after 500 cycles at 0.5 A/g.The superior electrochemical properties of LVO/C composite materials are attributed to the improved conductivity of electron and stable carbon/LVO composite structures.Besides,the LIC device based on activated carbon(AC) cathode and optimal LVO/C as anode reveals a maximum energy density of 110 Wh/kg and long-term cycle life.These results provide a potential way for assembling the advanced hybrid lithium-ion capacitors.
基金financially supported by the Applied Basic Research Project of Qinghai Province(No.2024-ZJ-766)the Youth Innovation Promotion Association CAS(No.2018466)
文摘Developing high-performance anode materials is crucial for the advancement of sodium-ion capacitors with high-energy density and large power density.Bimetallic oxides exhibit a high specific capacity due to their synergistic effects in electrochemical processes.However,challenges such as poor electrical conductivity,slow ion transport,and volume expansion severely limit their development.In this study,Co_(2)VO_(4)@C-1.5 was synthesized through a straightforward method involving solvent-heating and carbonization via calcination.The synergistic effect of Co and V,mitigation of volume expansion by the carbon-coated layer,enhancement of pseudocapacitive behavior and improved electrical conductivity of Co_(2)VO_(4)@C-1.5 contribute to its superior electrochemical performance.The specific capacity of Co_(2)VO_(4)@C-1.5 remained steady at 288.8 and 171.7 mAh g^(-1)after 100 and 500 cycles at 100 and 1000 mA g^(-1),respectively.Density functional theory(DFT)calculations show a notable reduction in the energy barrier of Co_(2)VO_(4)@C-1.5.Furthermore,the assembled sodium-ion capacitor Co_(2)VO_(4)@C-1.5//AC demonstrates high-energy density(108.5 Wh kg^(-1)at 99.8 W kg^(-1)),remarkable power density(38.2 Wh kg^(-1)at 12,000 W kg^(-1)),and longcycle stability(capacity retention of 80.6%after 6000 cycles).The design and optimization of the carbon-coated structure provide valuable insights for the development of bimetallic oxide materials in sodium-ion capacitors(SICs).
基金financially supported by the National Natural Science Foundation of China(Nos.52001059,52072119)Hunan Provincial Natural Science Foundation(No.2023JJ50015)the 111 Project(No.D20015)。
文摘A pseudocapacitance dominated anode material assembled from Li_(3)VO_(4)nanocrystals encapsulated in the interlayers of N-doped graphene has been developed via a facile 2D nanospace confined strategy for lithium ion capacitors(LICs).In this contribution,the N-doped graphene synthesized by a faicle solid state reaction using C_(3)N_(4)nanosheets as template and glucose as carbon source provides sufficient 2D nanospace for the confined and homogeneous growth of Li_(3)VO_(4)at the nanoscale,and simultaneously efficiently anchors each nanobuilding block inside the interlayers,thus realizing the utilizaiton of full potential of active components.The so-formed 3D hybrids not only ensure intimate electronic coupling between active materials and N-doped graphene,but also realize robust structure integrity.Owing to these unique advantages,the resulting hybrids show pseudocapacitance dominated lithium storage behaviors with capacitive contributions of over 90%at both low and high current rates.The LVO@C@NG delivers reversible capacities of 206 mAh/g at 10 A/g,capacity retention of 92.7%after 1000 cycles at 2 A/g,and a high energy density of 113.6 Wh/kg at 231.8 W/kg for LICs.
