In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale p...In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale production of nanoscale FeS2 are also essential. Based on above challenges, mesh-like FeS2/carbon tube/FeS2 composites are prepared simply from green, low-cost and renewable natural herb in this work. With the assistance of protogenetic interconnected carbon tube network(only 5.3 wt%), FeS2/carbon tube/FeS2 composites show high capacity(542.2 mA h g^-1), good stability(< 0.005% per cycle over 1000 cycles), and excellent rate performance(426.2 mA h g^-1 at 2 A g^-1).The outstanding electrochemical performance of FeS2/carbon tube/FeS2 composites may be attributed to the unique interconnected reticular structure, meaning that FeS2 nanoparticles are effectively immobilized by carbon tube network via physical encapsulation and chemical bonding.More importantly, this work may provide green and low cost preparation method for specially structured metal sulfides/carbon composites,which promotes their commercial utilization in environmentally friendly energy storage system.展开更多
Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in dev...Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in developing electrode materials enabling reversible Na+insertion/desertion and fast reaction kinetics.Herein,a core-shell structure,FeS2 nanoparticles encapsulated in biphase TiO2 shell(FeS2@TiO2),is developed towards the improvement of sodium storage.The diphase TiO2 coating supplies abundant anatase/rutile interface and oxygen vacancies which will enhance the charge transfer,and avoid severe volume variation of FeS2 caused by the Na+insertion.The FeS2 core will deliver high theoretical capacity through its conversion reaction mechanism.Consequently,the FeS2@TiO2 nanorods display notable performance as anode for SIBs including long-term cycling performance(637.8 m A·h·g^-1 at 0.2 A·g^-1 after 300 cycles,374.9 m A·h·g^-1 at 5.0 A·g^-1 after 600 cycles)and outstanding rate capability(222.2 m A·h·g^-1 at 10 A·g^-1).Furthermore,the synthesized FeS2@TiO2 demonstrates significant pseudocapacitive behavior which accounts for 90.7%of the Na+storage,and efficiently boosts the rate capability.This work provides a new pathway to fabricate anode material with an optimized structure and crystal phase for SIBs.展开更多
FeS2/Fe composites were mechanochemically prepared with iron powder and pyrite for the stabilization of ferrite arsenate sludge(FAS).The effects of preparation parameters on stabilization performance were investigated...FeS2/Fe composites were mechanochemically prepared with iron powder and pyrite for the stabilization of ferrite arsenate sludge(FAS).The effects of preparation parameters on stabilization performance were investigated.The results show that the optimum conditions are FeS2/Fe molar ratio of 5:5,milling time of 2 h,ball-to-material mass ratio of 15:1 and milling with stainless steel ball.Then,the composites were characterized by XRD,SEM,FTIR,etc.The physicochemical properties of FeS2/Fe mixture change dramatically,which is responsible for its excellent performance.Finally,the stabilization process of FAS was optimized.When the FAS is mixed with composites at mass ratio of 4:1 and milled for 30 min,the As leaching concentration of FAS can be reduced from 639.15 to 4.74 mg/L with the stabilization ratio of 99.2%.展开更多
Nano-spherical Co^（2＋）-doped FeS_2 was synthesized through a simple solvothermal method. The products were investigated using XRD, FE-SEM, BET, ICP, EDS, TEM, HRTEM, XPS, and UV-vis spectroscopy. The results indica...Nano-spherical Co^（2＋）-doped FeS_2 was synthesized through a simple solvothermal method. The products were investigated using XRD, FE-SEM, BET, ICP, EDS, TEM, HRTEM, XPS, and UV-vis spectroscopy. The results indicated that Co^（2＋） ion could change the particle nucleation process and inhibited the particle growth of FeS_2. In addition, when the content of doped Co^（2＋） was 15%, the degradation efficiency of methylene blue（MB） achieved 60.72% after 210 min irradiation, which increased by 52.01% than that of the undoped FeS_2. Moreover, comparison experiments also demonstrated that the M（M=Co^2＋,Co^2＋/Ni^2＋）-doped FeS_2 photocatalytic activity efficiency sequence was Co^（2＋） 〉 Ni^（2＋）〉Co^（2＋）/Ni^（2＋）. This is ascribed to the fact that the Co^（2＋） doping could induce the absorption edge shifting into the visible-light region and increased the surface area of the samples. The effect mechanisms of M-doping on the band gap and the photocatalytic activity of FeS_2 were also discussed.展开更多
FeS2 quantum-dots/functionalized graphene-sheet （QDs/FGS） composites are prepared by a facile and scalable method. The FeS2 QDs/FGS composites can be used as anode materials for sodium-ion batteries. The FeS2 QDs/FG...FeS2 quantum-dots/functionalized graphene-sheet （QDs/FGS） composites are prepared by a facile and scalable method. The FeS2 QDs/FGS composites can be used as anode materials for sodium-ion batteries. The FeS2 QDs/FGS composites can achieve large specific discharge and charge capacities of 742 and 683 mAh·g-1 （based on the total mass of the FeS2 QDs/FGS composites） at the current density of 0.5 A·g-1 in the first cycle, respectively, and retain a reversible charge capacity of 552 mAh·g-1 after 100 cycles. The FeS2 QDs/FGS composites can display high specific capacities of 452 and 315 mAh·g-1 at the high current densities of 2 and 5 A·g-1. These results indicate that the FeS2 QDs/FGS composites have good cycle performance and high rate capability, making them promising candidates as anode material for sodium-ion batteries.展开更多
基金supported by the Natural Science Foundation of China (Grant No. U1804126, U1804129, 21671205, 21771164 and 21701202)Key Scientific Research Projects of Universities in Henan Province (Grant No. 19A430032 and 18A430034)+2 种基金Program for Interdisciplinary Direction Team in Zhongyuan University of Technologythe Collaborative Innovation Centre of Henan Textile and Clothing Industrythe Innovation Scientists and Technicians Troop Construction Projects of Henan Province (Grant No. 164100510007 and CXTD2015018)
文摘In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale production of nanoscale FeS2 are also essential. Based on above challenges, mesh-like FeS2/carbon tube/FeS2 composites are prepared simply from green, low-cost and renewable natural herb in this work. With the assistance of protogenetic interconnected carbon tube network(only 5.3 wt%), FeS2/carbon tube/FeS2 composites show high capacity(542.2 mA h g^-1), good stability(< 0.005% per cycle over 1000 cycles), and excellent rate performance(426.2 mA h g^-1 at 2 A g^-1).The outstanding electrochemical performance of FeS2/carbon tube/FeS2 composites may be attributed to the unique interconnected reticular structure, meaning that FeS2 nanoparticles are effectively immobilized by carbon tube network via physical encapsulation and chemical bonding.More importantly, this work may provide green and low cost preparation method for specially structured metal sulfides/carbon composites,which promotes their commercial utilization in environmentally friendly energy storage system.
基金supported by the National Nature Science Foundation of China(No.51775366)。
文摘Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in developing electrode materials enabling reversible Na+insertion/desertion and fast reaction kinetics.Herein,a core-shell structure,FeS2 nanoparticles encapsulated in biphase TiO2 shell(FeS2@TiO2),is developed towards the improvement of sodium storage.The diphase TiO2 coating supplies abundant anatase/rutile interface and oxygen vacancies which will enhance the charge transfer,and avoid severe volume variation of FeS2 caused by the Na+insertion.The FeS2 core will deliver high theoretical capacity through its conversion reaction mechanism.Consequently,the FeS2@TiO2 nanorods display notable performance as anode for SIBs including long-term cycling performance(637.8 m A·h·g^-1 at 0.2 A·g^-1 after 300 cycles,374.9 m A·h·g^-1 at 5.0 A·g^-1 after 600 cycles)and outstanding rate capability(222.2 m A·h·g^-1 at 10 A·g^-1).Furthermore,the synthesized FeS2@TiO2 demonstrates significant pseudocapacitive behavior which accounts for 90.7%of the Na+storage,and efficiently boosts the rate capability.This work provides a new pathway to fabricate anode material with an optimized structure and crystal phase for SIBs.
基金Projects(2018YFC1900305,2018YFC1903301)supported by the National Key R&D Program of ChinaProject(51825403)supported by the National Natural Science Foundation for Distinguished Young Scholars of China+1 种基金Project(51634010)supported by the National Natural Science Foundation of ChinaProject(2017RS3010)supported by the Science and Technology Program of Hunan Province,China
文摘FeS2/Fe composites were mechanochemically prepared with iron powder and pyrite for the stabilization of ferrite arsenate sludge(FAS).The effects of preparation parameters on stabilization performance were investigated.The results show that the optimum conditions are FeS2/Fe molar ratio of 5:5,milling time of 2 h,ball-to-material mass ratio of 15:1 and milling with stainless steel ball.Then,the composites were characterized by XRD,SEM,FTIR,etc.The physicochemical properties of FeS2/Fe mixture change dramatically,which is responsible for its excellent performance.Finally,the stabilization process of FAS was optimized.When the FAS is mixed with composites at mass ratio of 4:1 and milled for 30 min,the As leaching concentration of FAS can be reduced from 639.15 to 4.74 mg/L with the stabilization ratio of 99.2%.
基金the National Natural Science Foundation of China(No.51372044)the Guangxi Distinguished Experts Special Fund,Guangxi Natural Science Foundation(No.2014GXNSFFA118004)the Improving the Basic Ability of Young and Middle-aged University Teachers in Guangxi(No.KY2016YB185)
文摘Nano-spherical Co^（2＋）-doped FeS_2 was synthesized through a simple solvothermal method. The products were investigated using XRD, FE-SEM, BET, ICP, EDS, TEM, HRTEM, XPS, and UV-vis spectroscopy. The results indicated that Co^（2＋） ion could change the particle nucleation process and inhibited the particle growth of FeS_2. In addition, when the content of doped Co^（2＋） was 15%, the degradation efficiency of methylene blue（MB） achieved 60.72% after 210 min irradiation, which increased by 52.01% than that of the undoped FeS_2. Moreover, comparison experiments also demonstrated that the M（M=Co^2＋,Co^2＋/Ni^2＋）-doped FeS_2 photocatalytic activity efficiency sequence was Co^（2＋） 〉 Ni^（2＋）〉Co^（2＋）/Ni^（2＋）. This is ascribed to the fact that the Co^（2＋） doping could induce the absorption edge shifting into the visible-light region and increased the surface area of the samples. The effect mechanisms of M-doping on the band gap and the photocatalytic activity of FeS_2 were also discussed.
基金This work was supported by National Natural Science Foundation of China （Nos. 51572129, U 1407106）, Natural Science Foundation of Jiangsu Province （No. BK20131349）, QingLan Project of Jiangsu Province, a project funded by the Priority Academic Program De- velopment of Jiangsu Higher Education Institutions （PAPD）, the Fundamental Research Funds for the Central Universities （No. 30915011204）
文摘FeS2 quantum-dots/functionalized graphene-sheet （QDs/FGS） composites are prepared by a facile and scalable method. The FeS2 QDs/FGS composites can be used as anode materials for sodium-ion batteries. The FeS2 QDs/FGS composites can achieve large specific discharge and charge capacities of 742 and 683 mAh·g-1 （based on the total mass of the FeS2 QDs/FGS composites） at the current density of 0.5 A·g-1 in the first cycle, respectively, and retain a reversible charge capacity of 552 mAh·g-1 after 100 cycles. The FeS2 QDs/FGS composites can display high specific capacities of 452 and 315 mAh·g-1 at the high current densities of 2 and 5 A·g-1. These results indicate that the FeS2 QDs/FGS composites have good cycle performance and high rate capability, making them promising candidates as anode material for sodium-ion batteries.
