Mass Transfer‐Enhanced Photothermal Membranes with Synergistic Light Utilization for High‐Turbidity Wastewater Purification

Abstract The photo‐Fenton process faces significant limitations in treating high‐turbidity, colored wastewater due to light attenuation and impurity interference (blocked mass transfer). To address these issues, we developed a suspended photothermal Fenton membrane by loading a photothermal catalyst on a hydrophobically modified cotton filter paper, enabling precise suspension 1 mm below the water surface. This design achieved 89.49 % light utilization and high chemical oxygen demand (COD) removal, even in wastewater with extreme chromaticity (10 multiples) and turbidity (703 NTU). The enhanced photothermal conversion accelerated molybdenum co‐catalyzed Fenton reactions and improved peroxymonosulfate (PMS) activation, maintaining over 90 % phenol removal for 15 days. Mechanistic simulations revealed improved mass transfer of reactive oxygen species (ROS) and pollutants at the solid–liquid interface, with PMS diffusion identified as the rate‐limiting step. The membrane resisted fouling from suspended solids and maintained stable operation in soil‐containing solutions for 10 days. This innovative approach offers an efficient solution for degrading pollutants in dark‐colored, high‐turbidity wastewater, overcoming traditional process limitations.