Synergistic CuO-CeO2 nanocomposites with narrow band gap for high-performance photocatalysis under solar light irradiation and antibacterial action

This research introduces a cost-effective method for synthesizing CuO-CeO 2 nanocomposites via hydrothermal processing, yielding particles with sizes of 20–30 nm. The nanocomposites exhibit impressive photocatalytic and antimicrobial properties. They demonstrate a direct band gap of 1.66 eV and possess a nano-spherical morphology, as verified by FE-SEM analyses. EDAX analysis reveals the presence of O, Ce, and Cu. Under optimized conditions (pH 7–8, 10 mg of catalyst, and 5 ppm of Orange G dye), the nanocomposites achieve 99.2% dye degradation under solar light, outperforming traditional binary oxides. Kinetic studies reveal a pseudo-first-order reaction, facilitated by the interaction between CuO and CeO 2 , that enhances charge separation and reactive oxygen species generation. Recyclability tests confirm strong stability, while antimicrobial tests indicate significant efficacy against various strains, including Salmonella typhimurium , Pseudomonas aeruginosa , and Enterobacter aerogenes , particularly at higher CuO ratios. These multifunctional nanocomposites show great potential for sustainable wastewater treatment and effective control of microbial contaminants.