ZnO/WO3.H2O micro-nanostructures coated mesh for efficient separation of oil-water mixture

• ZnO/WO 3 ·H 2 O coated stainless steel mesh was fabricated by hydrothermal method. • XPS analysis confirms + 2 and + 6 oxidation states of ZnO and WO 3 ·H 2 O respectively. • The deposited mesh showed superhydrophilic-underwater superoleophobic behavior. • ZnO/WO 3 ·H 2 O mesh with infused water layer efficiently separate oil-water mixtures. • The novel material could degrade the pollutant present in the filtrate water. In this work, we report the fabrication of superhydrophilic-underwater superoleophobic ZnO/WO 3 .H 2 O coated stainless steel mesh for the effective oil-water separation. X-ray diffraction studies confirm the occurrence of hexagonal wurtzite and orthorhombic phase of ZnO and WO 3 .H 2 O respectively in the ZnO/WO 3 .H 2 O coated mesh. The superhydrophilic-underwater superoleophobic nature of ZnO/WO 3 .H 2 O covered mesh is attributed to the innate hydrophilicity and surface roughness of WO 3 .H 2 O, which is again enhanced by the inclusion of ZnO. The oil-water separation efficiency of ZnO/WO 3 .H 2 O covered stainless steel mesh was over 98% for various oil-water mixtures. The coated mesh maintains high efficiency of separation even after 10 cycles of operation. Moreover, the as-deposited meshes demonstrated good separation ability for the emulsified oil droplets larger than its pore size. The excellent abrasion-resistant ability of ZnO/WO 3 .H 2 O coated mesh indicate its excellent mechanical stability. In addition, the high intrusion pressure of ZnO/WO 3 .H 2 O coated mesh favors the separation of oil-water mixture in large volumes. Furthermore, the photocatalytic activity of the coated mesh could degrade the organic pollutants present in the oil-water mixture. The proposed novel strategy in designing a multifunctional surface paves the way for the treatment of oleaginous water for environmental remediation.