Hydrothermal Synthesis of CuO/WO3 Hybrid Bifunctional Composites with Unprecedented Dark Adsorption and Photocatalysis

Abstract This study presents the synthesis and characterization of Copper Oxide/Tungsten Oxide (CuO/WO 3 ) hybrid bifunctional composites using a hydrothermal approach. X‐ray diffraction (XRD) analysis confirms the successful synthesis of CuO/WO 3 hybrids, exhibiting additional peaks corresponding to WO 3 phases. Scanning electron microscopy (SEM) images reveal well‐defined, aggregated particles with a nanoscale pattern and uniform distribution of CuO and WO 3 throughout the composite. Energy‐dispersive X‐ray spectroscopy (EDX) confirms the stoichiometric composition of CuO/WO 3 hybrids. Evaluation of dark adsorption and sunlight‐assisted photocatalysis using methylene blue (MB) dyes shows a remarkable enhancement in efficiency compared to pristine CuO. The CuO/WO 3 hybrids exhibit a dark adsorption capacity of 87 % and a photocatalytic degradation efficiency of 95 % under sunlight illumination, outperforming pure CuO. These results underscore the synergistic interaction between CuO and WO 3 , facilitating efficient pollutant removal. The study elucidates the structural properties and mechanistic insights driving the superior performance of CuO/WO 3 hybrid composites, offering promising prospects for advanced water treatment technologies.