Microwave-assisted synthesis of Ag/ZnO/diatomite composites for photocatalytic degradation of gaseous toluene

Abstract

In this work, a novel Ag/ZnO/diatomite composites was synthesized by microwave-assisted hydrothermal technique and used for the photocatalytic degradation of gaseous toluene. Various approaches were used to characterize the structural, morphological, optical and photoelectric properties of the composites. Photocatalytic degradation of gaseous toluene by Ag/ZnO/diatomite composites under visible-light irradiation was investigated. The experimental results demonstrate that the degradation efficiency of Ag/ZnO/diatomite composites reaches 90.4 %, which is better than that of ZnO/diatomite composites and ZnO. Ag/ZnO/diatomite composites have a pseudo-first-order rate constant of 0.01543 min⁻¹, which is 6.57 times more than that of ZnO. Through active species capture experiments, ·O₂⁻ and ·OH are the primary active species. Furthermore, the possible degradation mechanisms and pathways are proposed, the high performance of Ag/ZnO/diatomite composites can be attributed to the synergistic effect of ZnO, diatomite and Ag nanoparticles.