Plant stratum corneum inspired high-strength hydrogel coating modified palm skin by freezing and salting out strategy for efficient gravity-driven oil/water separation

•Bio-inspired strategy to improve the durability of biomass membrane was developed.•The bio-inspired modification strategy was facile, universal and eco-friendly.•Green and self-cleaning gravity-driven oil/water separation membrane was obtained.•The membrane had excellent efficiency, high flux and favorable reusability.•Our work provide new insight to enhance the tensile property of biomass membrane.