Nanocomposite: Co₄-substituted polyoxometalate@β-FeOOH as high-performance electrocatalysts for oxygen evolution reaction in alkaline conditions

A simple method to prepare Co₄POM@FeOOH-P nanocomposite has been explored by using the Keggin-type polyoxometalate (Co₄POM) doped β-FeOOH. Compared with the non-substituted POMs, transition metal substituted-POM would be a fatal factor to for improving the surface active sites of β-FeOOH. The nanocomposite exhibits the excellent electrochemical activity with a current density of 10 mA cm⁻² at 213 mV overpotential, a lowest Tafel slope of 47 mV dec⁻¹, and a excellent stability within 50 h in 1 M KOH. The Faraday efficiency is up to 97.6 %. The excellent electrocatalytic performance would be attributed to the multi-electronic structure of Co₄POM and the structural advantage of pores in β-FeOOH. Transition metal substituted-POM doped β-FeOOH in this study could be an effective strategy for preparing nanocomposite as the high-performance electrocatalysts for oxygen evolution reaction.