The defect-rich porous CoP4/Co4S3 microcubes as robust electrocatalyst for clean H2 energy production via alkaline overall water splitting

Abstract

Although water electrolysis is one of the most environmentally friendly methods for producing hydrogen (H2) and oxygen, designing robust non-noble electrocatalysts for overall water splitting remains a massive challenge. Modulating the morphology and chemical composition of non-noble-metal bifunctional electrocatalysts is an effective way to enhance catalytic activity in water electrolysis. Herein, a robust electrocatalyst with porous CoP4/Co4S3 microcubes rich in defects was synthesized through the phosphorylation and hydrothermal vulcanization of a Co–Co Prussian blue analog (Co–Co PBA). Given that the as-prepared CoP4/Co4S3 microcubes can provide additional active sites to accelerate electron transfer at the heterointerface, they exhibit enhanced catalytic activities in hydrogen and oxygen evolution reactions in 1.0 M KOH. When used as a bifunctional catalyst in a two-electrode electrolyzer, the micrucubesrequire a cell voltage of 1.67 V to achieve a current density of 10 mA cm−2 in 1.0 M KOH, indicating its potential as an efficient alkaline non-noble electrocatalyst for overall water splitting. This study provides a promising electrocatalyst for clean H2 energy production by modulating its morphology and chemical composition.