Fabrication of nanocrystalline high-entropy oxide CoNiFeCrMnOx thin film electrodes by dip-coating for oxygen evolution electrocatalysis

Abstract

The variation of calcination conditions allows for adjusting the oxidation states and coordination sites of near-surface elements in sol-gel-derived high-entropy oxides. Optimized synthesis conditions resulted in fabrication of nanocrystalline CoNiFeCrMnOx thin films with 1-2 nm pores, showing low OER overpotentials of 258 mV vs. RHE at 10 mA cm−2