Hierarchical 0D CuO Wrapped by Petal-like 2D ZnO: A Strategic Approach of Superhydrophobic Melamine Sponge toward Wastewater Treatment

In addressing the pressing environmental challenges posed by frequent oil spills, this work presents a novel approach of synthesizing a superhydrophobic three-dimensional (3D) porous melamine sponge (MS). CuO and ZnO nanoparticles were grown on the MS via a hydrothermal method to create MS/CuO/ZnO with multiscale hierarchical nanostructures. The resulting material exhibited a stable water contact angle of 155° through various tests. MS/CuO/ZnO demonstrated exceptional oil absorption capacities (40–145 g/g and 0.83–0.99 mL.cm–3), surpassing 98% efficiency in oil separation, and retained reusability for 10 cycles. Impressively, the sponge achieved successful separation of oil/water emulsions with a permeation flux of 14870 L m–2 h–1. The composite sponge, distinguished by its high photodegradation ability, can degrade both water- and oil-targeted pollutants under visible light irradiation from light-emitting diode (LED). With its remarkable attributes including superior oil absorption, excellent oil/water separation, mechanical resistance, and excellent photocatalytic ability, it exhibits considerable potential for applications in both wastewater treatment and large-scale marine oil spill response. The easily prepared MS/CuO/ZnO emerges as a versatile solution capable of addressing pressing challenges and marking a significant leap toward sustainable and impactful environmental remediation.