Membrane electrodes for electrochemical advanced oxidation processes: Preparation, self-cleaning mechanisms and prospects

The application of membrane electrodes in the electrochemical advanced oxidation processes (EAOPs) is becoming a hot topic of research, thanks to the membrane electrodes not only solve the bottleneck problems of poor mass transfer on the electrode surface and underutilized electroactive area of the electrode in traditional EAOPs, but also effectively alleviate the unavoidable membrane fouling in the traditional membrane filtration technology. The last decade has seen a rapid increase in the number of published papers on the application of membrane electrodes in EAOPs, but related review papers are still lacking. In this review, the preparation methods of membrane electrodes are briefly outlined. Membrane electrode materials (Carbon-based, metal/metal oxide-based and polymer-based conducive membrane) and strategies for improving membrane electrode performance are presented in detail. The application of membrane electrodes in various EAOPs (e.g., electro-oxidation, electro-Fenton, photo-electrocatalysis, electrocatalytic persulfate and electro-peroxone) and the involved mechanisms are discussed. The self-cleaning mechanisms of membrane electrodes during EAOPs are also summarized. Besides, the development prospects of membrane electrode in EAOPs are discussed. In brief, the paper presents an overview on the recent advances and prospects of the membrane electrodes for EAOPs.