Enhanced Fenton-like catalytic performance of freestanding CuO nanowires by coating with g-C3N4 nanosheets

A novel catalyst (CNCOF), consisting of dense CuO nanowires supported on copper foam and coated with multilayer g-C3N4 nanosheets, was developed as an exceptional Fenton-like catalyst. XRD, TEM, FTIR, and XPS results indicate that g-C3N4 nanosheets and CuO nanowires combine through van der Waals forces rather than chemical bonds. Adsorption-enhanced and structure-enhanced effects were both integrated into the CNCOF, endowing it with superior catalytic performance compared to CuO nanowire arrays. Mechanistic studies elucidated that the dyes first adsorb onto the g-C3N4 nanosheets and are subsequently degraded by •OH radicals diffused from the surface of CuO nanowires; a feature attributed to adsorption and structure enhancement of the CNCOF. The wide working pH range (3 to 9), simple recovery process and excellent recovery performance make CNCOF a supremely promising catalyst for remediation of organic pollutants in wastewater. Additionally, the improvement of Fenton-like performance through structural and adsorption enhancement provides a novel philosophy for catalyst design.