TiO2 photocatalytic ceramic membranes for water and wastewater treatment: Technical readiness and pathway ahead

TiO2 is one of the best-known environmentally friendly photocatalysts that has demonstrated the great potential to degrade a wide variety of organic foulants in water and wastewater treatment when placed under UV radiation. Currently, TiO2-based photocatalytic membranes are at the forefront of photodegradation research and technical readiness. The membrane setup provides a high contact surface area for effective filtration and degradation, without the necessary hassle of photocatalyst recovery after water and wastewater treatment. Meanwhile, TiO2 photocatalytic ceramic membranes have become an emerging research area due to the inherent chemical and mechanical stability of ceramic membranes, which enables them to outperform polymeric membranes. With the recent shift from polymeric to ceramic membranes in industrial applications, TiO2 photocatalytic ceramic membranes will become a key player among the next-generation ceramic membranes, as they are capable of multiple functionalities. This review provides a timely and focused Investigation Into the fabrication and application of such TiO2 photocatalytic ceramic membranes for water and wastewater treatment. The benefits of using photocatalytic ceramic membranes in filtration, such as a higher foulant removal efficiency, higher water permeability, and much improved antifouling capabilities, are highlighted and explained. Finally, the current research, technical readiness, and remaining gaps are identified, and a set of critical insights are provided using the available data to guide the developmental pathway of practical TiO2 photocatalytic ceramic membranes for water and wastewater treatment.