Synthesis and Mechanism of Z-Scheme Heterojunction Photocatalyst MoS2-WO3

Abstract

A novel spherical MoS2/WO3 composite was fabricated via a hydrothermal method for the photocatalytic degradation of RhB from wastewater. The structure and morphology of the photocatalyst were systematically characterized. The MoS2/WO3 nanospheres formed a p-n heterojunction, with charge migration following a Z-scheme mechanism. The MoS2/WO3 composites exhibited superior photocatalytic activity, achieving a 94.5% degradation rate for RhB in just 60 min under visible light irradiation, far surpassing the performance of pure WO3 and MoS2. This enhanced activity was attributed to the improved charge separation efficiency and redox capacity, enabled by the unique “layer–bending layer” growth mode. The composite’s transfer resistance (Rct) was as low as 7.42 × 102 Ω, promoting faster electrochemical reactions. With a maximum photocurrent density of 87 μA·cm−2, the composite rapidly separated photogenerated electron–hole pairs. The primary reactive species in the photocatalytic reaction were ·OH and O2−, with h+ playing a secondary role.