Robust and Thermally Stable Butterfly-Like Co(OH)₂/Hexadecyltrimethoxysilane Superhydrophobic Mesh Filters Prepared by Electrodeposition for Highly Efficient Oil/Water Separation

A superhydrophobic and superoleophilic material-modified stainless-steel (SS) mesh filter was successfully fabricated by the deposition of hierarchical butterfly-like micro/nanostructured Co(OH)₂ on the SS mesh with the unipolar pulse electrodeposition method, followed by modification with hexadecyltrimethoxysilane (HDTMS) and applied to the separation of hot and corrosive oil/water mixtures. The obtained Co(OH)₂/HDTMS SS mesh filter exhibited both superhydrophobicity (water contact angle as high as 157.9°) and superoleophilicity (oil contact angle of 0°) and excellent performance for the separation of oil/water mixtures under high temperature (up to 160 °C) and corrosive and ultrasonic conditions with long-term storage and reusability. It is expected that the present fabrication process could be applied to tuning the robust and thermally stable micro/nanostructures on the porous substrates for the oil/water separation under harsh conditions.