2-Methylimidazole-induced reconstruction of cobalt (oxy)hydroxide electrocatalysts toward efficient water oxidation

Electrochemical reconstruction of earth-abundant transition-metal-based precatalysts is a momentous approach to obtain high-performance oxygen evolution reaction (OER) catalysts. However, it still remains a formidable challenge to efficiently induce the reconstruction of OER catalysts toward enhanced electrocatalytic performance. In this work, a novel and simple 2-methylimidazole (2-MIM) treatment approach is demonstrated to promote the electrochemical reconstruction of cobalt layered double hydroxides. The 2-MIM modification enables an effective transformation into amorphous cobalt (oxy)hydroxides with abundant oxgen vacancies, which could afford enlarged electrochemical active surface and more active sites. As a result, the overpotential of the activated catalyst after in situ electrochemical reconstruction at 10 mA cm−2 is reduced by ~ 60 mV compared with that of the original counterpart. The present 2-MIM-assisted in situ electrochemical reconstruction strategy provide a fresh impetus for developing superior OER catalysts.