Biomimetic Porous CuO/ZnO S-Scheme Heterojunction for Highly Efficient Sunlight-Driven Photocatalytic Degradation of Rhodamine B

Sunlight-driven photocatalysis is at the forefront of sustainable technologies for the remediation of organic pollutants in industrial wastewater. In this study, we present the innovative synthesis of porous microspheres based on an S-scheme CuO/ZnO composite photocatalyst, inspired by the unique morphology of dried resurrection plants. X-ray diffraction confirmed the formation of highly crystalline CuO and ZnO phases, while UV-vis-NIR spectroscopy revealed exceptional sunlight harvesting capabilities, with optical absorption spanning the solar spectrum and a narrow bandgap of 1.4 eV. Under optimal conditions, the photocatalyst achieved a remarkable 97% degradation of Rhodamine B dye within just 60 min of solar irradiation. Systematic evaluation across varying compositions, pH values, and catalyst loadings highlighted robust photocatalytic performance. Moreover, the composite demonstrated outstanding stability and reusability, retaining high activity over more than five consecutive cycles. This full-solar-spectrum-active, biomimetic photocatalyst offers a promising platform for the efficient, sunlight-driven purification of hazardous organic effluents, with significant implications for environmental sustainability and public health.