Recent advances of two-dimensional CoFe layered-double-hydroxides for electrocatalytic water oxidation

Oxygen evolution reaction (OER) is pivotal to drive green hydrogen generation from water electrolysis, but yet is strictly overshadowed by the sluggish reaction kinetics. Earth-abundant and cut-price transition-metal compounds, particularly CoFe layered-double-hydroxides (LDHs), show the distinct superiorities in contrast to noble metals and their derivatives. In this review, we firstly underline their fundamental issues in electrocatalytic water oxidation, including CoFe LDHs crystal structure, the surface of (hydr)oxides confined to OER and the controversial roles of Fe species, aiming at understanding the structure-related activity and catalytic mechanism. Advanced approaches for optimizing OER activity of CoFe LDHs are then comprehensively overviewed, which will shed light on the different working mechanisms and provide a concise analysis of their unique advantages. Finally, a perspective on the future development of CoFe LDHs electrocatalysts is offered. We hope this review can give a concise and explicit guidance for the development of transition-metal-based electrocatalysts in the energy field.