Dual‐Function Electrocatalysis: Simultaneous Wastewater Remediation and Hydrogen Evolution—A Comprehensive Review

Abstract

The simultaneous escalation of global energy demand and environmental pollution necessitates innovative technologies that address both challenges in an integrated manner. Conventional water electrolysis for green hydrogen production is hampered by the high energy input required to drive the kinetically sluggish oxygen evolution reaction (OER). This comprehensive review explores the transformative strategy of dual‐function electrocatalysis, which replaces the anodic OER with the electro‐oxidation of organic and inorganic pollutants in wastewater. This approach not only significantly lowers the cell voltage for efficient hydrogen evolution but also enables the simultaneous remediation of contaminated water. We meticulously detail the fundamental principles and recent advancements in coupling the hydrogen evolution reaction (HER) with the oxidation of a wide spectrum of waste substrates, including urea, hydrazine, alcohols, aldehydes, ammonia, amines, and carbohydrates. A critical analysis reveals that the rational design of earth‐abundant electrocatalysts is pivotal to overcoming kinetic barriers and achieving high selectivity in these complex reactions. This review examines major classes of electrocatalysts, including transition metals, their alloys, oxides/(oxy)hydroxides, phosphides, sulfides, nitrides, and noble‐metal hybrids. For each class, we discuss how alloying/heteroatom doping, nano‐architecturing, defect engineering, and electronic modulation are used to enhance performance. Overall, these advances indicate that waste‐oxidation‐assisted HER can be developed into a practical low‐voltage route to hydrogen that also upgrades real wastewater streams. They further show that catalyst design rules from fundamental studies can be implemented in electrochemical systems suitable for scale‐up.