Synthesis of TiO2/MoSx/Ag nanocomposites via photodeposition for enhanced photocatalysis and membrane fouling mitigation

Abstract

In this research, to improve photocatalytic organic pollutant removal, we synthesized amorphous MoSx (a-MoSx) and Ag on TiO2 via a two-step photodeposition method. The As-synthesized TiO2/a-MoSx/Ag (TMA) photocatalyst exhibited a highly enhanced photocatalytic degradation performance of methylene blue which showed 3.6 times higher reaction rate constant than that of TiO2 photocatalyst. Furthermore, TMA photocatalyst was applied to the ultrafiltration (UF) membrane to mitigate fouling of the membrane. To realize a stable immobilization of photocatalyst on the membrane surface, polydopamine (PDA), which is a biocompatible mussel-inspired adhesive material, was utilized to form an adhesive layer. After PDA coating, TMA photocatalyst was stably deposited on the UF membrane, resulting to increased hydrophilicity. Fouling was successfully mitigated by photocatalytic self-cleaning property of TMA deposited UF membrane and flux recovery ratio was improved by 28% under irradiation. Owing to the simple and easy approach of both photodeposition-based heterostructure photocatalyst synthesis and post-processing of photocatalyst coating on the membrane, we present that our strategy for membrane fouling mitigation is suitable for future membrane technology.