Bionic engineering-induced formation of hierarchical structured minerals with superwetting surfaces for oil-water separation

Harnessing the living organisms to fabricate the biomimetic materials with hierarchical ordered structures via biomineralization process shows great potential in oil-water separation. Herein, we exploited a bacteria-assisted mineralization strategy with environmental friendliness to realize the growth of the CaCO3 minerals with hierarchical micro/nanostructures on the stainless steel meshes (SSMs). The biomimetic CaCO3 minerals coated-SSMs (CaCO3-SSMs) owned superhydrophilicity and underwater superoleophobicity with water contact angles of nearly 0° and underwater oil contact angles of up to 161°. The CaCO3-SSMs showed excellent oil-water separation performance with ultrahigh permeation flux (1.55 × 105 L m−2 h−1) and high separation efficiency (≥98.5%), while concurrently demonstrating high chemical and mechanical stability. Furthermore, the CaCO3-SSMs possessed ultralow oil-adhesion force in water, endowing them with outstanding anti-oil fouling property. We expect that the bionic engineering-induced formation of the minerals with hierarchical structures could help for the development of next generation superwetting materials.