Hierarchical BiVO4/Cu(OH)2 nanocone/nanowire membrane with environmental durability and electro-/photo- cleaning capability for oil/water separation

Abstract

Oil spills and waste oily water draining have aroused adverse effects on ecosystem, environmental safety and human health. Separation membranes with high efficiency and antifouling ability are highly desired to separate oil/water mixtures. Herein, biomimetic hierarchical BiVO4/Cu(OH)2 nanocone/nanowire dual-structure is anchored on conductive Cu mesh (BV/CW@CM). The BV/CW@CM membrane with open porous structure and roughness surface behaves excellent superhydrophilicity and underwater superoleophobicity, as well as performs good electrocatalytic oxygen evolution and photocatalytic degradation capability to eliminate surface organic pollutants. Therefore, the BV/CW@CM exhibits high water flux (≥45 kL m−2 h−1), high separation efficiencies (≥99.8%), and good electroflotation cleaning capability (bubbles removal contaminations within 1 min) and photocatalytic degradation ability (kerosene degradation within 70 min). Moreover, due to the protective coating of ultrasmall BiVO4 nanocones, the membrane exhibits excellent stability under harsh environments, including salty, acid/base, calcination, and surface friction. The high oil/water separation capability, good environmental durability and excellent electro-/photo- cleaning capability demonstrate the extensive potential applications of the membranes under various environmental conditions.