Transition Metal-Based Electrocatalysts for Seawater Oxidation

Electrocatalytic water splitting is an effective strategy, which can convert intermittent energy such as wind energy and solar energy into renewable and sustainable hydrogen energy. Global freshwater resources are extremely scarce. Compared with freshwater, seawater is a rich and sustainable resource, and it has attracted more and more attention in electrocatalysis. However, the oxygen evolution reaction (OER) is a four-electron transfer process, which leads to slow reaction kinetics. Moreover, the presence of various elements in seawater and their interference to electrochemistry make the OER in seawater extremely challenging. Herein, the latest progress in the development of transition metal-based OER electrocatalytic materials for seawater is reviewed by hydroxides, oxides, chalcogenides, phosphides, and nitrides. Focus is made on how to eliminate competitive reaction chlorine evolution reaction of OER in electrolytic seawater. The recent research advances of OER catalyst for selective electrolysis seawater are summarized from the aspects of structure design, mechanism understanding, and performance enhancement strategy. Finally, the challenges, prospects, and research directions of seawater electrocatalysis for OER are introduced.