Novel Engineered Carbon Cloth-Based Self-Cleaning Membrane for High-Efficiency Oil–Water Separation

Abstract

A novel engineered carbon cloth (CC)-based self-cleaning membrane containing a Cu:TiO2 and Ag coating has been created via hydrothermal and light deposition methods. The engineered membrane with chrysanthemum morphology has superhydrophilic and underwater superhydrophobic performance. The cooperativity strategy of Cu doping and Ag coating to the TiO2 is found to be critical for engineering the separation efficiency and self-cleaning skill of the CC-based membrane under visible light due to the modulated bandgap structure and surface plasmon resonance. The CC-based membrane has excellent oil–water separation performance when Cu is fixed at 2.5 wt% and the Ag coating reaches a certain amount of 0.003 mol/L AgNO3. The contact angle of underwater oil and the separation efficiency are 156° and 99.76%, respectively. Furthermore, the membrane has such an outstanding self-cleaning ability that the above performance can be nearly completely restored after 30 min of visible light irradiation, and the separation efficiency can still reach 99.65% after 100 cycles. Notably, the membrane with exceptional wear resistance and durability can work in various oil–water mixtures and harsh environments, indicating its potential as a new platform of the industrial-level available membrane in dealing with oily wastewater.

Advanced Self-Cleaning Surfaces

“…Such surfaces also proved efficient in protecting stainless steel from concentrated HCl [7]. The specular concept, i.e., developing a superhydrophilic and underwater superoleophobic surface, was applied to obtain oil-water separation with a carbon cloth membrane coated with Cu-doped TiO 2 and Ag nanoparticles [8]. Water treatment was the objective of another study, based on melt-blending an ethylene-vinyl alcohol copolymer and polypropylene to produce hydrophilic hollow fibres, which were successfully tested for ink separation [9].…”