Amorphous CoFePOx hollow nanocubes decorated with g-C3N4 quantum dots to achieve efficient electrocatalytic performance in the oxygen evolution reaction.

Abstract

Simultaneously enriching active sites and enhancing intrinsic activity in a simple way is of great importance for the design of highly active electrocatalysts for the oxygen evolution reaction (OER), but it still faces challenges. Herein, g-C3N4 quantum dot decorated amorphous hollow CoFe bimetallic phosphate nanocubes (a-CoFePOx@CNQD) are prepared as an efficient OER electrocatalyst by a simple in situ etching-phosphating process. Research shows that their unique hollow architecture and amorphous structure can help provide generous exposed active sites for OER, and the incorporation of g-C3N4 quantum dots can effectively adjust the electronic structure to improve the intrinsic activity. Therefore, a-CoFePOx@CNQD exhibits excellent OER performance with a low overpotential (239 mV) at 10 mA cm-2 and a small Tafel slope (58.4 mV dec-1), surpassing the commercial RuO2. Furthermore, a-CoFePOx@CNQD as an electrode catalyst for a water electrolyzer and zinc-air battery also shows higher performance and stability than RuO2 + Pt/C catalysts. This study provides a feasible strategy for preparing efficient and stable amorphous hollow heterostructure OER electrocatalysts.