Enhancing Photocatalytic and Antibacterial Properties through a Synergistic Approach in ZnS-CuSe Nanocomposites.

Abstract

This study introduces a novel single-step sonochemical synthesis method for producing pure ZnS and CuSe. Moreover, it offers a comprehensive first-time report on the fabrication of ZnS-CuSe nanocomposites with varying compositions via using a wet-chemical method. Comprehensive characterization was conducted to assess the material's phase purity, structure integrity, composition, detection of free radicals, and optical properties. The results revealed that the average crystallite sizes of ZnS and CuSe were determined to be 46.91 and 20.31 nm, respectively. Morphological analysis showed that CuSe formed nanoflakes structure, whereas ZnS was observed as nanoparticles. The optical properties revealed a red shift in the absorption spectra and a corresponding decrease in the band gap with varying CuSe concentration.  The electrons in the CBM (conduction band minimum) can be directly captured by •O2 to produce large amounts of •O2- and •OH radicals, which are formed via the route of •O2- →H2O2 →•OH. Further insights from DFT calculations agree with these findings and offer a deeper understanding of how CuSe affects the electronic structure of ZnS materials. Moreover, among the materials, the CZ-3 nanocomposite showed superior photocatalytic activity, achieving 98% degradationof methylene blue(MB) dyeand effective inhibition of B. subtilis and P. aeruginosa under visible light irradiation.