Achieving a strong redox ability and high visible-light absorption ability in a single semiconductor material is difficult.Designing a heterojunction between two semiconductor materials is a feasible method.The new st...Achieving a strong redox ability and high visible-light absorption ability in a single semiconductor material is difficult.Designing a heterojunction between two semiconductor materials is a feasible method.The new step(S-scheme)heterojunction can effectively promote the separation and trans-fer of photogenerated electron-hole pairs and retain strong redox ability.We designed and pre-pared a Cd Se_(0.8)S_(0.2)-diethylenetriamine(DETA)/Sn Nb_(2)O_(6)heterostructure material via the sol-vothermal method.When Cd Se_(0.8)S_(0.2)-DETA and Sn Nb_(2)O_(6)form an S-scheme heterojunction,30%Cd Se_(0.8)S_(0.2)-DETA/Sn Nb_(2)O_(6)exhibits the highest CO production rate(17.31μmol·g^(-1)·h^(-1)),which is factors of 2.8 and 4.8 higher than that of traditional solvothermal Sn Nb_(2)O_(6)(6.2μmol·g^(-1)·h^(-1))and Cd Se_(0.8)S_(0.2)-DETA(3.6μmol·g^(-1)·h^(-1)),respectively.X-ray photoelectron spectroscopy characterization data provided evidence that the transfer pathway of space charge in the CO_(2)reduction process was in accordance with the S-scheme.This research provides a simple strategy through which one can optimize the band structure to promote the separation of photogenerated carriers and achieve a high efficiency of CO_(2)reduction.展开更多
Free-standing electrodes are promising candidates for flexible rechargeable batteries, toward the application of flexible energy storage devices, due to their merits of additive-free, lightweight, and high energy dens...Free-standing electrodes are promising candidates for flexible rechargeable batteries, toward the application of flexible energy storage devices, due to their merits of additive-free, lightweight, and high energy density. Herein, we report a free-standing SnNb_(2)O_(6)@CSN flexible film with SnNb_(2)O_(6) encapsulated in 3D carbon skeleton nanofibers by electrospinning and carbonization processes as flexible anode for sodium-ion batteries(SIBs). The 3D carbon skeleton nanofibers serve as ion/electron transport pathway to improve the electrochemical reaction kinetics and meanwhile alleviate the volume changes of SnNb_(2)O_(6) during charge-discharge processes. The as-constructed half-cell(SnNb_(2)O_(6)@CSN‖Na) exhibits excellent cycling stability of 99.2 m Ah/g at 0.5 A/g after 950 cycles(coulombic efficiency of ~100%) and a high rate performance of 108.6 mAh/g at 10 A/g. In addition, the pouch cell can light up the LEDs at different bending angles(0°, 90°, 180°). This research shows a promising anode material for flexible energy storage electronics.展开更多
文摘Achieving a strong redox ability and high visible-light absorption ability in a single semiconductor material is difficult.Designing a heterojunction between two semiconductor materials is a feasible method.The new step(S-scheme)heterojunction can effectively promote the separation and trans-fer of photogenerated electron-hole pairs and retain strong redox ability.We designed and pre-pared a Cd Se_(0.8)S_(0.2)-diethylenetriamine(DETA)/Sn Nb_(2)O_(6)heterostructure material via the sol-vothermal method.When Cd Se_(0.8)S_(0.2)-DETA and Sn Nb_(2)O_(6)form an S-scheme heterojunction,30%Cd Se_(0.8)S_(0.2)-DETA/Sn Nb_(2)O_(6)exhibits the highest CO production rate(17.31μmol·g^(-1)·h^(-1)),which is factors of 2.8 and 4.8 higher than that of traditional solvothermal Sn Nb_(2)O_(6)(6.2μmol·g^(-1)·h^(-1))and Cd Se_(0.8)S_(0.2)-DETA(3.6μmol·g^(-1)·h^(-1)),respectively.X-ray photoelectron spectroscopy characterization data provided evidence that the transfer pathway of space charge in the CO_(2)reduction process was in accordance with the S-scheme.This research provides a simple strategy through which one can optimize the band structure to promote the separation of photogenerated carriers and achieve a high efficiency of CO_(2)reduction.
基金financially supported by the National Natural Science Foundation of China (Nos. 51774251, 22179077)the Natural Science Foundation in Shanghai (No. 21ZR1424200)+2 种基金the Shanghai Science and Technology Commission's "2020 Science and Technology In-novation Action Plan" (No. 20511104003)the Hebei Natural Science Foundation for Distinguished Young Scholars (No. B2017203313)the Scientific Research Foundation for the Returned Overseas Chinese Scholars (No. CG2014003002)。
文摘Free-standing electrodes are promising candidates for flexible rechargeable batteries, toward the application of flexible energy storage devices, due to their merits of additive-free, lightweight, and high energy density. Herein, we report a free-standing SnNb_(2)O_(6)@CSN flexible film with SnNb_(2)O_(6) encapsulated in 3D carbon skeleton nanofibers by electrospinning and carbonization processes as flexible anode for sodium-ion batteries(SIBs). The 3D carbon skeleton nanofibers serve as ion/electron transport pathway to improve the electrochemical reaction kinetics and meanwhile alleviate the volume changes of SnNb_(2)O_(6) during charge-discharge processes. The as-constructed half-cell(SnNb_(2)O_(6)@CSN‖Na) exhibits excellent cycling stability of 99.2 m Ah/g at 0.5 A/g after 950 cycles(coulombic efficiency of ~100%) and a high rate performance of 108.6 mAh/g at 10 A/g. In addition, the pouch cell can light up the LEDs at different bending angles(0°, 90°, 180°). This research shows a promising anode material for flexible energy storage electronics.
