Self-assembly of Cu-glutathione nanoparticles on WO3 nanorods: amelioration of charge transfer and photocatalytic performance

The substitution of noble metals with cost-effective copper nanoparticles (Cu NPs) in the preparation of metal/semiconductor composite catalysts holds significant environmental and economic implications for the degradation of various organic pollutants. However, the development of highly active and stable Cu NPs catalysts has emerged as a key challenge in the progression of non-noble metal catalysts. In this study, the reducibility of glutathione (GSH) was employed to reduce Cu²⁺ to Cu NPs, resulting in the formation of stable Cu-GSH nanoparticles through S–H bonds. An electrostatic self-assembly strategy was used to load Cu-GSH onto WO₃ nanorods, thereby designing a Cu GSH/WO₃ catalytic material with highly efficient charge transport efficiency. Under visible light irradiation, 3 wt% Cu GSH/WO₃ demonstrated excellent degradation performance for organic pollutants, achieving the degradation of 99.8% of Rh B and 98.6% of TC within 60 minutes. Experimental results from photoelectrochemical (PEC) and electron spin resonance (ESR) analyses indicated that Cu GSH functions as an efficient electron trap, which triggers electron flow driven by the Schottky barrier, capturing the photoexcited electrons from WO₃. This greatly enhances the separation efficiency of WO₃ carriers and extends the lifetime of the carriers. It is hoped that this work will provide a viable approach for the synthesis of new high-efficiency composite photocatalytic materials.