Construction of CeO2@CuO@Cu2O step scheme heterostructure photocatalyst for cationic dye degradation and microbial inactivation

Water pollution caused by toxic organic compounds and bacterial contamination has become a serious global challenge. In this study, a visible-light-activated dual-character heterostructure photocatalyst (CeO 2 @CuO@Cu 2 O) was synthesized using a hydrothermal method. The crystallinity, morphology, elemental composition, porosity, and energy band gap of the material were analyzed using XRD, TEM, EDX, BET, and UV–visible DRS techniques, respectively. The photocatalytic activities of CeO 2 @CuO@Cu 2 O and its individual components were evaluated for the degradation of methylene blue (MB) dye. Pure CeO 2 NPs alone was unable to degrade MB photocatalytically; however, in combination with Cu 2 O, 97.5 % degradation was achieved within 120 min. Antimicrobial stabilizers, quercetin and ascorbic acid, were used for the preparation of CeO 2 and Cu 2 O, respectively. The antimicrobial potential of the CeO 2 @CuO@Cu 2 O photocatalyst was examined against E. coli , S. Typhimurium , E. faecalis , and B. subtilis , with respective MIC values of 0.75–1.0, 0.75–1.0, 1.0–1.25, and 0.8–1.0 mg/mL. Furthermore, cell viability studies on HEK 293 kidney cell lines revealed that CeO 2 @CuO@Cu 2 O maintained cell viability of up to 91.56 %. The reduced toxicity of CeO 2 @CuO@Cu 2 O was further supported by the normal growth of green gram plants under its influence. • Sun-light-active CeO 2 @CuO@Cu 2 O heterostructure photocatalyst was synthesized using a hydrothermal method. • Heterostructure achieved 97.5 % degradation of methylene blue within 120 min. • Heterostructure exhibited notable antimicrobial activity against multiple pathogenic bacteria. • Cell viability and phytotoxicity studies demonstrated low toxicity and strong biocompatibility of CeO 2 @CuO@Cu 2 O.