Transforming Co3O4 nanosheets into porous N-doped CoxOy nanosheets with oxygen vacancies for the oxygen evolution reaction

Cobalt oxides have been widely investigated as promising replacements for noble metal-based catalysts for oxygen evolution reaction(OER). Herein, we, for the first time, have obtained porous CoOnanosheets with N-doping and oxygen vacancies by etching CoOnanosheets with NHplasma. Comparing with the pristine CoOnanosheets(1.79 V), the porous CoOnanosheets with N-doping and oxygen vacancies have a much lower potential of 1.51 V versus RHE to reach the current density of 10 mA cm. The obtained sample has a lower Tafel slope of 68 m V decthan the pristine CoOnanosheets(234 mV dec).The disclosed Co, which is responsible for the formation of active sites(CoOOH), N-doping and oxygen vacancies, gives rise to better performance of OER.