Improved photocatalytic activity of ZnO via the modification of In2O3 and MoS2 surface species for the photoreduction of CO2

Abstract Herein, a series of In2O3 and MoS2 surface-bound active species co-modified using ZnO nanorods (ZnO–In2O3X%/MoS2Y%) were synthesized via a hydrothermal method. X-ray diffraction (XRD), High–resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV–Vis absorption, and fluorescence spectroscopy, as well as time-resolved photoluminescence decay curves, have shown that In2O3 and MoS2 were the active species co-modified on the surface of ZnO. The band structure of the resulting photocatalysts was determined via characterization experiments combined with theoretical calculations, and the behavior of the photo-generated electrons and holes were investigated. We noted that the In2O3 and MoS2 surface-bound active species generated transfer channels for the holes and electrons, respectively. For the CO2 photoreduction reaction, the ZnO–In2O3X%/MoS2Y% photocatalysts exhibited improved performance due to the contribution of the surface species during the efficient separation of the photo-generated electrons and holes; this enhanced the visible light absorption capacity and, thus, the catalyst's band structure matching with the redox potential of CO2 photoreduction. This paper provides a new strategy for designing and preparing novel photocatalysts with surface-bound active sites and high photocatalytic performance.