Layered Double Hydroxides for Oxygen Evolution Reaction towards Efficient Hydrogen Generation

Electrochemical water splitting is one of the effective ways to obtain highly pure hydrogen. However, as one of the two half reactions, oxygen evolution reaction (OER) has a high overpotential, resulting in the low-energy utilization efficiency. Therefore, numerous electrocatalysts have been developed to reduce the energy barrier of OER. Among them, layered double hydroxides (LDHs) are excellent OER electrocatalysts with flexible composition and structure, which have been widely investigated in the past decade. Recent studies have been focusing on the identification of active sites for LDHs during OER process, trying to reveal clear reaction mechanism for designing more efficient LDHs electrocatalysts. Hence, this review tries to discuss the advances in identifying active site of LDHs based OER electrocatalysts for efficient hydrogen generation. We first introduce the effect of structure, composition, and defects to the OER performance of LDHs. Furthermore, main attention is paid on the active sites and mechanisms during OER, especially the coordination structures and catalytic mechanisms of active sites. At the end of this review, we put forward the existing problems and shortcomings in this fields, and propose the corresponding solutions, aiming to further promote the development of outstanding OER electrocatalysts towards efficient hydrogen production.