Fabrication of a robust superhydrophobic stainless steel mesh for efficient oil/water separation

Abstract

Selective oil removal from water is a critical problem in the realm of environmental science and engineering. Metallic meshes are commonly used as potential oil–water separators due to their low cost and good mechanical properties. Meshes with selective wettability can effectively remove oil or water from their mixtures easily using gravity-based filtration. In this work, a mechanically robust Ni-WS2 based superhydrophobic stainless steel mesh (SHSM) has been developed via one-step electrodeposition. The surface morphologies, surface roughness, phase composition, and wettability were studied using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray diffraction (XRD), and Water Contact Angle (WCA) measurements respectively. A high water contact angle of 169.5° with excellent superhydrophobic and superoleophilic properties was achieved by tuning the surface morphology of the mesh. The oil/water separation performance of the developed SHSM was studied and the efficiency was greater than 98% even after multiple uses. Further, the SHSM is highly corrosion-resistant and exhibits self-cleaning properties with excellent mechanical and chemical stability against strong acidic/alkaline solutions. Thus, the developed multifunctional SHSM demonstrates its potential at industrial-level applications of oil–water separation under harsh environments.