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
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.
