Two-dimensional Sn2Ta2O7 nanosheets with a thickness of^10 nm were successfully prepared through a novel tantalic acid-based solid-state reaction method at reduced temperature.The as-obtained samples were characterize...Two-dimensional Sn2Ta2O7 nanosheets with a thickness of^10 nm were successfully prepared through a novel tantalic acid-based solid-state reaction method at reduced temperature.The as-obtained samples were characterized by powder X-ray diffraction(XRD),ultraviolet–visible(UV–Vis)diffuse reflectance spectra,scanning electron microscopy(SEM),transmission electron microscopy(TEM)and Brunauer–Emmett–Teller(BET)analysis.The photocatalytic performance of Sn2 Ta2 O7 nanosheets was evaluated by photocatalytic water splitting for hydrogen evolution under visible light irradiation(k C 400 nm).The Sn2Ta2O7 nanosheets with a large surface area of 25.9 m^2·g^-1 showed higher H2 production activity,which was about 4.4 times higher than that of bulk Sn2 Ta2O7 in lactic acid aqueous solutions using Pt as a cocatalyst.The improved photocatalytic performance mainly benefited from the nanosheet structure,which provided abundant surface active sites and facilitated the photogenerated charge carrier separation efficiently.This workmay open up new opportunity to develop novel nanostructured tantalum-based semiconductors with improved catalytic performance for solar energy conversion.展开更多
The detailed theoretical studies of electronic,optical,and mechanical properties of γ-Bi2Sn2O7 are carried out by using first-principle density functional theory calculations.Our calculated results indicate that γ-B...The detailed theoretical studies of electronic,optical,and mechanical properties of γ-Bi2Sn2O7 are carried out by using first-principle density functional theory calculations.Our calculated results indicate that γ-Bi2Sn2O7 is the p-type semiconductor with an indirect band gap of about 2.72 e V.The flat electronic bands close to the valence band maximum are mainly composed of Bi-6s and O-2p states and play a key role in determining the electrical properties of γ-Bi2Sn2O7.The calculated complex dielectric function and macroscopic optical constants including refractive index,extinction coefficient,absorption coefficients,reflectivity,and electron energy-loss function show that γ-Bi2Sn2O7 is an excellent light absorbing material.The analysis on mechanical properties shows that γ-Bi2Sn2O7 is mechanically stable and highly isotropic.展开更多
Herein,AgLi1/3Sn2/3O2 with delafossite structure was prepared by treating the layered compound Li2 SnO3 with molten AgN03 via ion exchange of Li^+for Ag^+.The structure characterization and the electrochemical perform...Herein,AgLi1/3Sn2/3O2 with delafossite structure was prepared by treating the layered compound Li2 SnO3 with molten AgN03 via ion exchange of Li^+for Ag^+.The structure characterization and the electrochemical performance of AgLi1/3Sn2/3O2 was thoroughly investigated.AgLi1/3Sn2/3O2 is found to possess stacking lamellar morphology,which means small electrochemical impedance and so facilitates charge transfer kinetics during the cycling.Compared with Li2 Sn03,due to the introducing of excellent electrical conductivity of silver,AgLi1/3Sn2/3O2 exhibits improved electrochemical performance in terms of capacity,cycling stability and coulombic efficiency.The results show AgLi1/3Sn2/3O2 presents favorable specific capacity of 339 mAh/g at current density of 200 mA/g after 50 cycles and initial coulombic efficiency of 96%.Exsitu XRD analysis revealed the reaction mechanism of AgLi1/3Sn2/3O2 as an anode for lithium ion batteries.展开更多
Ternary nanocomposites of CuxZnySnzS(x+y+z)are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal struc...Ternary nanocomposites of CuxZnySnzS(x+y+z)are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability.Recently,this nanocomposite used as anode material for Li-ion battery has been reported,but there is lim让ed research on让s application in supercapacitors which is considered a complementary energy storage device to battery.In this work,flower-like Cu5Sn2S7/ZnS and pristine Cu5Sn2S7 nanocomposite were prepared via a facile hydrothermal method.The electrochemical tests showed that the Cu5Sn2S7/ZnS nanocomposite exhibited better performance than pristine Cu5Zn2S7,suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu5Sn2S7,with the good capacitance of 200 F/g at the current density of 1 A/g.Furthermore 170 F/g was obtained at the large current density of 10 A/g.Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.展开更多
The magneto-caloric effect （MCE） of a Gd55Co25Al18Sn2 bulk metallic glass （BMG） is investigated. The Gd55Co25AllsSn2 as-cast rod prepared by a water-cooled copper mold suction casting method exhibits typi- cal amo...The magneto-caloric effect （MCE） of a Gd55Co25Al18Sn2 bulk metallic glass （BMG） is investigated. The Gd55Co25AllsSn2 as-cast rod prepared by a water-cooled copper mold suction casting method exhibits typi- cal amorphous characteristics. The maximum magnetic entropy change （--ASPmeak） and the magnetic refrigerant capacity （Re） of the BMG under a field of 5 T are about 9.32 J.kg-X.K 1 and 832 J.kg-1, respectively, both of which are larger than the values of the Gd55 Co25A120 BMG. The mechanism for the improved MCE by minor Sn addition is studied and the field dependence of - magneto-caloric behaviors of Gd55Co25Al18Sn2 BMG ASPmeak is investigated for a better understanding on the展开更多
基金financially supported by the National Key R&D Program of China (Nos. 2017YFA0206904, 2017YFA0206900 and 2016YFB0600901)the National Natural Science Foundation of China (Nos. 51825205, U1662118, 51772305, 51572270, 21871279 and 21802154)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB17000000)the Beijing Natural Science Foundation (No. 2182078), the Beijing Municipal Science and Technology Project (No. Z181100005118007)the Royal Society-Newton Advanced Fellowship (No. NA170422)the International Partnership Program of Chinese Academy of Sciences (No. GJHZ1819)the K. C. Wong Education Foundation
文摘Two-dimensional Sn2Ta2O7 nanosheets with a thickness of^10 nm were successfully prepared through a novel tantalic acid-based solid-state reaction method at reduced temperature.The as-obtained samples were characterized by powder X-ray diffraction(XRD),ultraviolet–visible(UV–Vis)diffuse reflectance spectra,scanning electron microscopy(SEM),transmission electron microscopy(TEM)and Brunauer–Emmett–Teller(BET)analysis.The photocatalytic performance of Sn2 Ta2 O7 nanosheets was evaluated by photocatalytic water splitting for hydrogen evolution under visible light irradiation(k C 400 nm).The Sn2Ta2O7 nanosheets with a large surface area of 25.9 m^2·g^-1 showed higher H2 production activity,which was about 4.4 times higher than that of bulk Sn2 Ta2O7 in lactic acid aqueous solutions using Pt as a cocatalyst.The improved photocatalytic performance mainly benefited from the nanosheet structure,which provided abundant surface active sites and facilitated the photogenerated charge carrier separation efficiently.This workmay open up new opportunity to develop novel nanostructured tantalum-based semiconductors with improved catalytic performance for solar energy conversion.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB643703)the National Natural Science Foundation of China(Grant Nos.11164005,11464008,and 51401060)+1 种基金the Natural Science Foundation of Guangxi Zhuang Autonomous Region,China(Grant Nos.2014GXNSFGA118001 and 2012GXNSFGA060002)the Fund from Guangxi Provincial Key Laboratory of Information Materials of Guangxi Zhuang Autonomous Region,China(Grant Nos.1210908-215-Z and 131022-Z)
文摘The detailed theoretical studies of electronic,optical,and mechanical properties of γ-Bi2Sn2O7 are carried out by using first-principle density functional theory calculations.Our calculated results indicate that γ-Bi2Sn2O7 is the p-type semiconductor with an indirect band gap of about 2.72 e V.The flat electronic bands close to the valence band maximum are mainly composed of Bi-6s and O-2p states and play a key role in determining the electrical properties of γ-Bi2Sn2O7.The calculated complex dielectric function and macroscopic optical constants including refractive index,extinction coefficient,absorption coefficients,reflectivity,and electron energy-loss function show that γ-Bi2Sn2O7 is an excellent light absorbing material.The analysis on mechanical properties shows that γ-Bi2Sn2O7 is mechanically stable and highly isotropic.
基金supported by Natural Science Foundation of Jiangsu Province of China (No.BK20170982)the National Natural Science Foundation of China(No.51601080)
文摘Herein,AgLi1/3Sn2/3O2 with delafossite structure was prepared by treating the layered compound Li2 SnO3 with molten AgN03 via ion exchange of Li^+for Ag^+.The structure characterization and the electrochemical performance of AgLi1/3Sn2/3O2 was thoroughly investigated.AgLi1/3Sn2/3O2 is found to possess stacking lamellar morphology,which means small electrochemical impedance and so facilitates charge transfer kinetics during the cycling.Compared with Li2 Sn03,due to the introducing of excellent electrical conductivity of silver,AgLi1/3Sn2/3O2 exhibits improved electrochemical performance in terms of capacity,cycling stability and coulombic efficiency.The results show AgLi1/3Sn2/3O2 presents favorable specific capacity of 339 mAh/g at current density of 200 mA/g after 50 cycles and initial coulombic efficiency of 96%.Exsitu XRD analysis revealed the reaction mechanism of AgLi1/3Sn2/3O2 as an anode for lithium ion batteries.
基金the support via Postgraduate Research Award of Queensland University of Technology(QUTPRA)
文摘Ternary nanocomposites of CuxZnySnzS(x+y+z)are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability.Recently,this nanocomposite used as anode material for Li-ion battery has been reported,but there is lim让ed research on让s application in supercapacitors which is considered a complementary energy storage device to battery.In this work,flower-like Cu5Sn2S7/ZnS and pristine Cu5Sn2S7 nanocomposite were prepared via a facile hydrothermal method.The electrochemical tests showed that the Cu5Sn2S7/ZnS nanocomposite exhibited better performance than pristine Cu5Zn2S7,suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu5Sn2S7,with the good capacitance of 200 F/g at the current density of 1 A/g.Furthermore 170 F/g was obtained at the large current density of 10 A/g.Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51171100 and 51271103
文摘The magneto-caloric effect （MCE） of a Gd55Co25Al18Sn2 bulk metallic glass （BMG） is investigated. The Gd55Co25AllsSn2 as-cast rod prepared by a water-cooled copper mold suction casting method exhibits typi- cal amorphous characteristics. The maximum magnetic entropy change （--ASPmeak） and the magnetic refrigerant capacity （Re） of the BMG under a field of 5 T are about 9.32 J.kg-X.K 1 and 832 J.kg-1, respectively, both of which are larger than the values of the Gd55 Co25A120 BMG. The mechanism for the improved MCE by minor Sn addition is studied and the field dependence of - magneto-caloric behaviors of Gd55Co25Al18Sn2 BMG ASPmeak is investigated for a better understanding on the
