The direct Z-scheme Cd_xZn_(1-x)S nanorods-Fe_2O_3 quantum dots heterojunction/reduced graphene oxide nanocomposites for photocatalytic degradation and photocatalytic hydrogen evolution

摘要

In this paper, we reported a simple hydrothermal strategy to prepare the direct Z-scheme CdxZn1-xS nanorods-Fe2O3 quantum dots heterojunction/reduced graphene oxide (CdxZn1-xS-FG) nanocomposites as the multifunctional photocatalysts for photocatalytic degradation of organic dyes and photocatalytic hydrogen evolution. By adjusting the molar mass ratio of Cd2+ and Zn2+ ions from 9:1 to 1:9, the bandgap of the CdxZn1-xS-FG nano composites can be turned from 2.23 to 3.49 eV. The Cd0.3Zn0.7S-FG nanocomposites exhibited the highest H-2 evolution rate of 26.8 mmol h(-1) g(-1) and the highest degradation efficiency of 97.32% towards MB in 120 min under the visible light irradiation. The excellent photocatalytic activity can be attributed to the high-efficiency transportation and separation of the photogenerated electron-hole pairs, more catalytic active sites and large specific surface area. The mechanism of the photocatalytic hydrogen evolution and photocatalytic degradation had been investigated by ultraviolet photoelectron spectroscopy, scavenging experiment, and UV-Vis absorption spectra. Considering the unique structure, morphology, and excellent photocatalytic performances of the CdxZn1-xS-FG nanocomposites, it will become a burning star in the field of photocatalysis.