Nanosecond laser ablation for enhanced adhesion of CuO nanowires on copper substrate and its application for oil-water separation

Abstract

Nanotextured materials have been used extensively for water treatment and purification to minimize wastewater pollution from factories and oil spill accidents from damaging our ecosystem. With constant erosion from the environment, the adhesion of nanomaterials to surfaces has thus been a long-standing challenge for practical deployment in industrial settings. Thermally-induced oxidative growth of copper oxide (CuO) nanowires (NWs) on Cu foil is a readily accessible and scalable technique of mass producing nanostructures. However, the NWs readily exfoliate from the substrate, limiting its utilization. The use of a pulsed 1064 nm laser texturing approach to greatly improve adhesion and sturdiness of CuO NWs array on Cu foil with laser fabricated microholes is presented. This is a catalyst-free and controllable process to create functional surfaces with microholes lined with hierarchical CuO NWs array. The resultant superhydrophilic nano-textured surface demonstrated the ability as an efficient filter for potential applications in separation of oil-water emulsions. It achieves enhanced speed of separation withstanding higher intrusion pressure and higher efficiency. This work has a great potential for scalable applications in high-efficiency oily wastewater treatment, underwater oil manipulation, self-cleaning and bioadhesion control.