Fabrication of Bi2S3@Bi2WO6/WO3 ternary photocatalyst with enhanced photocatalytic performance: synergistic effect of Z-scheme/traditional heterojunction and oxygen vacancy

摘要

Both the fabricating of heterojunction and oxygen vacancy are the effective methods for boosting the performance of semiconductor photocatalyst. However, the fast recombination of charge carriers and limited light absorption in ubiquitous binary heterojunction are still inherent problems that hinder the practical application of photocatalysts. Herein, a ternary heterojunction of Bi2S3@Bi2WO6/WO3 was fabricated by the facile hydrothermal route combining with an in-situ growth method, and was confirmed by employing elemental mapping and high-resolution transmission electron microscopy. The oxygen vacancy was introduced into Bi2S3@Bi2WO6/WO3 ternary heterojunction as demonstrated by X-ray photoelectron spectroscopy. Compared with Bi2S3@Bi2WO6/WO3 samples, the obtained Bi2S3@Bi2WO6/WO3 composites exhibited higher photocatalytic activity in photodegrading rhodamine B and Tetracycline. The high photocatalytic activity was attributed to the synergistic effect of Z-scheme/traditional heterojunction and oxygen vacancy that extended the visible-light absorption range and promoted the effective separation of photo-generated electron-hole pairs. Based on the trapping experiments and calculated positions of energy band, the photocatalytic mechanisms of the Z-scheme/traditional heterojunction with oxygen vacancy were also proposed. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.