2D/2D/3D architecture Z‑scheme system for simultaneous H2 generation and antibiotic degradation

Abstract

The construction of p-n heterojunction is a workable approach for the expansion of light absorption range and the suppression of charge-carrier recombination to enhance the photocatalytic performance. However, the redox ability of dominant band potential in each semiconductor is restrained by heterostructure. In this work, the reduced graphene oxide (RGO) was used as an adhesive to integrate Cu2O and BiVO4 via a two-step solvothermal method, fabricating a Z-scheme photocatalytic system. The 2D/2D/3D Cu2O/RGO/BiVO4 system exhibited excellent photocatalytic performance on simultaneous tetracycline degradation (TC) and H2 production due to the high redox ability. The highest H2 production achieved by the 7/G40/3 sample was about 6 times higher than that of Cu2O with the TC degradation rate of 20.3%. In the whole degradation, the 7/G40/3 sample also exhibited the optimal degradation efficiency for TC of 96% after 3 h under visible light irradiation. And various experimental and test results demonstrated that RGO played a significant role in the combination of the conduction band electrons of BiVO4 and the valence band holes of Cu2O, enriching electrons and holes in the dominant energy band, respectively. This study highlights the rational integration of H2 production and pollutant degradation by taking full advantage of the Z-scheme photocatalytic system.