The optimized oxygen evolution reaction of FeCoNi layer double hydroxide by the adhesion of Ag nanoparticles

Modulating the morphological structure and establishing heterogeneous interface of layered double hydroxides (LDHs) are feasible strategies in electrocatalytic oxygen evolution reaction (OER). In this work, FeCoNi-LDH nanosheets are synthesized on the surface of copper foam (CF) by a simple electrodeposition method, where cross-linked nanosheets were aggregated into microspheres and then uniformly loaded with Ag nanoparticles. The unique heterogeneous interface between Ag nanoparticles and FeCoNi-LDH was demonstrated by TEM characterization. The electrochemical results show that the Ag@FeCoNi-LDH@CF is an efficient OER electrocatalyst in alkaline media. The required overpotential at 100 mA/cm2 is not only significantly lower than that of FeCoNi-LDH@CF but also superior to most of recently reported OER electrocatalysts. The results of XPS and BET indicate that the introduction of Ag nanoparticles accelerates the electron transfer and optimizes the activity of the original sites, thus improving the efficiency of the OER catalyst. It is also experimentally verified that Ag@FeCoNi-LDH@CF can maintain its stability after a long time of chronoamperometry cycling, which shows good prospects for future practical applications. Therefore, this finding suggests that the targeted assembly of noble metals and transition metals into a system to construct new OER electrocatalysts with integrated improvements is an effective design approach to improve the OER performance of LDHs.