High performance visible light response 0D/2D MoS2QDs/BiOCl photocatalyst with synergetic effects of up-conversion and direct Z-scheme heterojunction

Abstract

Constructing Z-scheme heterojunction has been regarded as a fascinating method to enhance the charge carrier separation rate and retain the high photoredox ability. In this paper, a novel 0D/2D MoS2QDs/BiOCl Z-scheme heterojunction with outstanding visible-light photocatalytic performance has been successfully prepared by a facile one-step strategy. The MoS2QDs with a diameter of 5 nm were uniformly distributed on the surface of BiOCl nanosheets. The optimized MoS2QDs/BiOCl heterojunction showed the most robust CIP and RhB degradation efficiency, which was approximately 32.2 and 44.7 times higher than that of pure BiOCl under visible light irradiation, respectively. This result can be attributed to the synergetic effects of up-conversion and direct Z-scheme heterojunction of the MoS2QDs. The optical property, morphology and surface feature of the catalyst were analyzed through the UV–vis DRS, PL, XRD, Raman, FT-IR, XPS, SEM and TEM. The study of ESR characterization and free radical capture experiments confirmed the Z-scheme heterojunction electron transfer route. Finally, a rational photocatalytic mechanism for pollutants degradation over the MoS2QDs/BiOCl heterojunctions were proposed. This study may provide a reliable strategy for the construction of Z-scheme bismuth-based heterojunction and its potential application in photocatalytic organic pollutants degradation.