Review—Understanding and Controlling Charge Functions in Materials for Electrochemically Mediated Water Treatment

Abstract

Water management by electrochemical means has attracted increasing attention due to the high energetic efficiency and significantly improved water treatment efficacy of related emerging technologies. Charge functions in electronic and electrochemical materials dictate the overall water treatment performance such as selectivity, operation stability, removal capacity and rate. In this review, we elucidate the design principles of charge-functional materials for electrochemically mediated water treatment by considering fundamental performance-governing processes, including charge transport, surface adsorption, bulk ion insertion and (photo)electrocatalysis. Furthermore, we highlight the recent development of in situ operando imaging tools for probing these critical processes that occur during water treatment, with a particular focus on functional imaging techniques capable of probing local charge-functional parameters (e.g., charge carrier diffusivity, pollutant adsorption affinity, and redox reaction rate) to establish local structure-function relationships. We conclude this review article by pointing out the opportunities and challenges that warrant future research in order to further improve the performance and scale-up ability of electrochemical water treatment technologies in the broader context of the energy-environment nexus toward a sustainable zero-carbon future.