Controlled Fabrication of Au@Nh2-Mil-125(Ti)/Cds with Enhanced Photocatalytic Ability for the Degradation of Mb

Abstract

The application of CdS in pollutant degradation is limited due to the rapid compounding of photogenerated carriers. A ternary Au@NH 2 -MIL-125(Ti)/CdS (5Au@40NMT/CdS) composite catalyst is synthesized by a two-step method and its photocatalytic performance was evaluated by degradation of methylene blue (MB) under simulated visible light conditions. The composite of NH 2 -MIL-125 and the loading of Au nanoparticles significantly enhance the photodegradation performance of the composite catalyst. Compared with pure CdS, the degradation rate of the ternary composite product is 93.3% within 30 min, which also enhances the degradation rate by 9 times and shows a good recycling performance. In addition, superoxide radical (·O 2 - ) is identified as the main active species in the MB degradation process by the electron spin resonance (ESR) technique. The factors responsible for the enhanced photocatalytic performance are elucidated, and the corresponding degradation mechanisms and models are proposed. This work is expected to provide inspiration for the fabrication and design of CdS/MOF composite catalysts in the field of pollutant degradation.

Keywords: Photodegradation, 5Au@40NMT/CdS, Methylene blue