Synergistic integration of Ag and porous carbon into ZrO₂ coating for self-cleaning and durable oil–water separation

A superhydrophilic/underwater superoleophobic Ag/ZrO₂-PC coating was fabricated on stainless steel mesh. • The coating exhibits a separation efficiency of >99.9% and a flux of 1.82 × 10 4  L·m −2 ·h −1 . • Efficiency remains >98.7% under acid, alkali, and saline conditions. • Photocatalytic self-cleaning recovers surface wettability (51° → 13.8°) under visible light. As environmental pollution intensifies and water quality regulations become increasingly stringent, the development of efficient separation technologies has emerged as a critical priority. In this study, Ag/ZrO 2 -PC (AZPC) composite coatings with photocatalytic self-cleaning properties were fabricated on stainless-steel meshes via metal-organic deposition combined with hydrothermal processing, enabling highly efficient oil-water separation. The resultant coatings exhibit a micro−/nano-scale rough topography, which impacts superhydrophilicity (water contact angle (WCA) of 0°) and underwater superoleophobicity (underwater oil contact angle (UOCA) of 161°). The composite membrane achieves an oil-water separation efficiency exceeding 99.9%, with a maximum permeation flux of 1.82 × 10 4  L·m −2 ·h −1 . After 20 separation cycles, the membrane retains a separation efficiency above 98.6% for different oil-water mixtures, demonstrating excellent cyclic stability. Furthermore, after 60 min of visible-light irradiation, the surface WCA decreased significantly from 51° to 13.8°, thereby demonstrating superior self-cleaning capability. Collectively, these findings indicate that the as-prepared composite material demonstrates outstanding stability and durability, rendering it highly promising for practical applications in high-efficiency oil-water separation.