Bimetallic nanostructure-functionalized membranes coupled with sulfate radical-based advanced oxidation processes: Fabrication strategies, characterizations, and applications

Advances in heterogeneous advanced oxidation processes are hindered by various challenges, such as mass transfer limitations, nanoparticle aggregation, short lifetimes of reactive oxygen species (ROS), and leaching of nanoparticles. Bimetallic nanoparticle-functionalized membranes coupled with advanced oxidation processes (BNPFM-AOPs) are the most suitable and efficient solutions because of their simultaneous destruction and mineralization of pollutants, facile separation and recovery of catalyst, affordability, microbe deactivation, and membrane antifouling properties. BNPFM-AOPs have improved oxidant-nanocatalyst interactions, ROS-pollutant interactions, and rapid ROS diffusion rates than conventional heterogeneous AOPs, resulting in increased ROS yields, reduced matrix effects, and faster degradation rates. This review overviews fabrication methods (blending, surface coatings, bottom-up synthesis, and in-situ synthesis), characterization techniques (composition, morphology, structure, and performance), and potential applications. A review of recent advances in oxidant activation and removal mechanisms for heavy metals, antibiotics, and organic pollutants is presented. It also highlights membrane fouling and cleaning mechanisms, reaction kinetics, and toxicity assessment. Furthermore, the scope, challenges, and recommendations are discussed. This study is anticipated to advance our understanding of BNPFM-SR-AOP chemistry, fabrication methods, characterization techniques, degradation rates, and toxicity.