Seedless hydrothermal growth of piezoelectric photocatalytic ZnO nanowires on laser-ablated copper mesh for oil/water separation

ZnO is an efficient catalyst in water pollution treatment and can be obtained by hydrothermal reaction. In this work, ZnO nanoflowers assembled by orderly grown nanowires have been fabricated on the copper sheet surface after laser treatment by using a zinc solution, eliminating the step of seed layer growth. After laser ablation, the copper sheet can produce oxidized nanoparticles, which can be used as the active growth site for the synthesis of ZnO nanowires. The growth behavior of ZnO nanowires varied in different regions around the laser heat-affected zone, where the fabricated ZnO nanowires range in the diameters of 200-300 nm and lengths of 1-4 mu m. The ZnO nanowires-decorated copper mesh has stable underwater oleophobic performance. The surface roughness of copper mesh is adjusted to form a dual-functional membrane with 99% oil-water separation efficiency and 70% piezoelectric photocatalytic cooperative degradation efficiency, which could provide potential multifunctional materials for novel microfluidics.