Electrochemically responsive materials for energy-efficient water treatment and carbon capture

Electrochemically responsive materials (ERMs) that respond to external electrical stimuli offer advanced control over physio-chemical processes with a high degree of tunability and flexibility. Recently, the use of ERMs in environmental remediation processes has increased to address the grand sustainability challenges associated with water scarcity and climate change. Here, we provide a timely review on the applications of ERMs to electrochemically mediated water treatment (EMWT) and electrochemically mediated carbon capture (EMCC). We first examine the working principles of ERMs-based systems for water treatment and carbon capture, followed by a detailed summary of key figures of merit that quantify the overall performance. Second, we present an in-depth discussion of the multiscale design principles of EMWT and EMCC systems, ranging from materials-level engineering to electrode-level considerations to device configuration optimization. Next, we discuss the development and application of in situ and operando characterization methods, with a particular emphasis on imaging tools, which uncover ubiquitous static and dynamic heterogeneities in ERMs and critically inform rational materials design. Finally, we point out future opportunities and challenges in the emerging field of electrochemically mediated environmental remediation, including developing new tools to monitor complex multiphase transport and reactions, repurposing existing energy nanomaterials for environmental technologies, and scaling and combining EMWT and EMCC systems.