Microstructure collapse: A shortcut to skip lengthy cyclic voltammetric activation in oxygen evolution reaction

Abstract

This work outlines a simple yet ingenious approach to enhance performance of catalysts and stabilization in oxygen evolution reaction (OER) by rapidly disrupting microstructure. Prussian blue analogue (PBA) nanospheres (NS), designed as advanced electrocatalysts, are based on Ni3S2@FeCoNi and phosphorization. Thermal oxidation can allow NS to undergo microstructural collapse and form nanorubble (NR). NR obtained at 325 °C has a lower overpotential (230.0 mV) than NS. The material reaches its optimum condition directly, skipping tedious cyclic voltammetric (CV) activation. Collapse has regular properties, which are evidenced in some materials. No significant performance degradation during 1000 h (j = 10 mA cm−2) and 24 h (j = 500 mA cm−2) of electrolysis confirms excellence of this unconventional pathway. Theoretical calculations show the exposure of amorphous state from collapse enriches charges on the material surface, which helps to promote transformation of intermediates at the catalytic microinterfaces and accelerates the reaction process.