BACKGROUNDRecently, some smart superwetting materials with switchable wettability have attracted great interest due to their ability to controllably separate oil/water mixtures. However, the fabrication of most smart materials requires complex procedures and precious chemical reagents for surface modification, limiting large-scale engineering applications of the fabricated smart surface. RESULTSIn this study, a silver surface was prepared by extremely simple displacement deposition on copper mesh. The silver-coated mesh exhibits superhydrophobicity and superoleophilicity after heating treatment, which allows oil to permeate while blocking water. Interestingly, the heated silver-coated mesh gains superhydrophilic and underwater superoleophobic properties after UV irradiation, which allows water to permeate but prevents oil. As a consequence, the as-fabricated mesh is capable of achieving two completely different oil/water separation processes. In addition, the silver-coated mesh shows excellent environmental stability under a series of harsh conditions. CONCLUSIONA novel smart engineering material with UV-induced switchable wettability was successfully fabricated. In view of the rapid and simple fabrication approach, it is envisaged that this work will provide a promising prospect of large-scale production in smart oil/water separation materials. (c) 2017 Society of Chemical Industry