Synthesis of a core-shell heterostructured MoS2/Cd0.9Zn0.1S photocatalyst for the degradation of diclofenac under visible light

Abstract

The development of novel noble metal-free semiconductor catalysts with high photocatalytic efficiency is of great importance toward the degradation of organic compounds. In this work, a core-shell heterojunction MoS2/Cd0.9Zn0.1S photocatalytic material was successfully synthesized via a simple one-step hydrothermal method. The introduction of MoS2 led to a significant improvement in the photocatalytic degradation of diclofenac (DCF). It was confirmed that 0.1% loading content of MoS2 achieved an optimal photocatalytic efficiency of 86% in the degradation of DCF under visible light irradiation, which was 1.8 times higher than that of Cd0.9Zn0.1S. The MoS2/Cd0.9Zn0.1S heterostructured composites possessed improved photocatalytic properties, which implied that the combination of Cd0.9Zn0.1S and MoS2 shortened the carrier transport pathway and facilitated the separation efficiency of electrons and holes. Reactive species (RS) scavenging experiments and electron spin resonance (ESR) demonstrated that superoxide radicals (O2•−) and electron holes (h+) played predominant roles throughout the DCF degradation process. The primary intermediates were explored through HRAM LC/MS/MS, and a transformation pathway was tentatively proposed. This study promoted the application of an economical, highly efficient and visible light driven MoS2 co-catalyst for the degradation of organic contaminants.