Wodyetia bifurcate structured carbon fabrics with durable superhydrophobicity for high-efficiency oil-water separation

Abstract

The superhydrophobic fiber-based membranes with features of high separation efficiency and low energy consumption for oil-water separation remains a formidable challenge. In this paper, a robust and durable superhydrophobic cotton-derived carbon fabric (CDCF) with wodyetia bifurcate-like structure is fabricated via in situ cobalt-nickel basic carbonate (CNC) deposition and 1 H, 1 H, 2 H, 2 H-perfluorooctyltriethoxysilane (POTS) coating. The combined action of rough surface structure and low surface energy makes CDCF/CNC/POTS with superhydrophobicity/superoleophilicity, anti-wetting, and self-cleaning performance. Intriguingly, the CDCF/CNC/POTS can keep its superhydrophobicity under of the water droplet impact pressure of 781 Pa. In addition to its robust dynamic superhydrophobicity, CDCF/CNC/POTS can also maintain its non-wetting property under harsh environmental conditions such as mechanical abrasion treatment, acidic, alkaline and salt solutions, and ultraviolet radiation. Importantly, the CDCF/CNC/POTS can separate various oil-water mixtures and emulsions under gravity with ultrahigh oil-water mixtures permeate flux (∼19,126 L/m2h), high surfactant-stabilized emulsion permeate flux (∼821 L/m2h), and high separation efficiency (> 98.60 %). Moreover, remarkable recyclability endow the CDCF/CNC/POTS with promising application in treating oily wastewater. This work may benefit the low-cost mass production of cotton-based carbon fabrics for developing eco-friendly high-efficiency separators.