Flexible g-C3N4-based photocatalytic membrane for efficient inactivation of harmful algae under visible light irradiation

Development of immobilized composite photocatalysts for efficient inactivation of algal cells is important because of the features of easy recycling and high stability. Herein, ultrathin g-C3N4 (SCN) are embedded into cellulose acetate (CA) matrix to form CA/SCN composite membranes. The obtained photocatalytic membranes exhibit the properties of thickness uniformity, flexible and higher light absorption compared to the bulk one. Under visible light, 92% of algal can be removed by the optimal CA/SCN photocatalytic membrane (CA/SCN-200). During photocatalytic algal inactivation, algal cells occur photosynthetic activity decrease, antioxidant system collapse and membrane damage. In addition, algal organic matters and MC-LR can also be removed during the photocatalytic process. More importantly, large area membrane which also exhibits high algal removal performance can be prepared easily. This work provides a new way to develop high performance photocatalytic membranes for algal removal.