Recent Advances in Photocatalytic TiO <sub>2</sub> -based Membranes for Eliminating Water Pollutants
Yanchao Xu, Sin Ling Chiam, C.P. Leo, Zhen Hu
Abstract
Photocatalysis dominated by TiO2 photocatalysts offers innovative solutions to improve membranes that are susceptible to membrane fouling caused by efficiency and lifespan limitations. TiO2-based membranes have been initially developed to enhance membrane separation and antifouling properties, but they later evolved into photocatalytic membranes that can efficiently degrade pollutants using light energy. This review covers recent advancements in TiO2-based photocatalytic membranes for water treatment through surface modification and blending after comparing the latest works on TiO2 photocatalyst modification. Photocatalyst modification techniques such as ion doping, noble metal doping, and semiconductor composites have effectively enhanced TiO2 photocatalysts. The TiO2-based photocatalytic membranes showed significant efficacy in oil-water separation when MIL-100(Fe), carbon dopants, and g-C3N4 were incorporated. They also demonstrated effective dye removal by incorporating rGO and MXene. Additionally, TiO2-based photocatalytic membranes successfully removed antibiotics and emerging contaminants after being modified with Fe3O4, g-C3N4, and Ag. TiO2-based photocatalytic membranes have been tested in oil-water separation and industrial wastewater treatment, addressing pollutants like dyes and emerging contaminants. More engineering designs of photocatalytic membrane reactors should be developed to ensure efficient absorption of light energy, and photoelectrocatalysis may be considered in future works.