Emerging electrocatalysts for electrochemical advanced oxidation processes (EAOPs): recent progress and perspectives

The global water crisis is among the most pressing challenges facing humankind. Identifying and developing cost-effective and environmentally friendly water remediation technologies are crucial for water reclamation. Electrochemical advanced oxidation processes (EAOPs) relying on oxidation by reactive species, such as hydroxyl radicals (OH), O-3, H2O2, HClO, etc., have been recognized as an appealing and promising decentralized approach for on-site treatment of water containing a wide range of organic contaminants. Recent advances in nanotechnology have stimulated extensive research on investigating efficient, durable and energy-saving electrocatalysts/electrodes for EAOP applications. This review aims to provide an overview of the recent progress in wastewater treatment using electrochemical technologies with a particular focus on EAOPs that have demonstrated high efficiency in the removal of various types of recalcitrant organics from contaminated water. The state-of-the-art electrocatalysts based on different systems of EAOPs were critically evaluated and summarized, and the impacts on catalytic activity, removal efficiency, performance stability, and product selectivity were systematically discussed. Challenges and opportunities that arise at the intersection of materials science and treatment process engineering were proposed, as future research would aim to enhance catalyst properties while considering the primary roadblocks such as the expense and sustainability of practical EAOP implementation in water decontamination.