Prussian blue analogue assisted formation of iron doped CoNiSe₂ nanosheet arrays for efficient oxygen evolution...

Electrochemical water splitting is a promising approach to produce hydrogen gas, but sluggish four-electron transfer of the oxygen evolution reaction (OER) severely limits the overall energy conversion efficiency of water splitting. Herein, as an excellent OER electrocatalyst, a technique of synthesizing Fe doped CoNiSe₂ nanosheet (Fe-CoNiSe₂) whole series using CoFe prussian blue analog produced by Co-ZIF-L reaction as a template is proposed here. The introduction of iron ions promotes the redistribution of the cobalt-nickel charge density, which enhances the OER kinetics. In view of the abovementioned points, Fe-CoNiSe₂/NF has excellent activity, electrocatalytic properties and excellent stability in alkaline media, which only demands a lower overpotential of 244 mV and 271 mV to deliver a current density of 10 mA cm^-2 and 50 mA cm^-2, respectively. The material also exhibits excellent stability for at least 24 h during the OER process. This work may provide some new insights into the assembly of advanced and highly-active materials for a variety of other energy conversion applications.