Bi₂S₃‑Nanowire-Sensitized\nBiVO₄ Sheets for Enhanced Visible-Light Photoelectrochemical\nActivities

Abstract

BiVO₄ is\nwidely used for photoelectrochemistry and photocatalytic\noxygen evolution under visible-light irradiation. To extend the range\nof visible-light absorption and reduce the recombination rate of photoexcited\nelectrons and holes, a BiVO₄ sheet–Bi₂S₃ nanowire heterostructure\nwas fabricated through an easy in situ hydrothermal method. In this\nmethod, Bi₂S₃ nanowires were uniformly coated\nonto the surface of BiVO₄ sheets. The heterostructure exhibits\na wide visible-light absorption band ranging from 525 to 900 nm after\ncoupling with Bi₂S₃ nanowires. The BiVO₄ sheet–Bi₂S₃ nanowire heterostructures\nwere used for photoelectrochemical measurements and exhibited higher\nphotocurrent intensity than those of BiVO₄ sheets and BiVO₄ particle–Bi₂S₃ under visible-light\nirradiation. The optimized amount of Bi₂S₃ in\nthe heterostructure was approximately 2.4 at. %. The remarkable enhancements\nin the photoelectrochemical property were attributed mainly to the\nsolid sensitization of Bi₂S₃ nanowires providing\na number of photoexcited electrons, shortening transport distance\nin BiVO₄ sheets, smoothening migration along Bi₂S₃ nanowires, and enhancing the synergistic effect between\nBiVO₄ and Bi₂S₃.