Fe and Cr doped porous Co3O4@C nanosheets with abundant oxygen vacancies for highly efficient oxygen evolution reaction

Transition metal oxides have received much attention in the field of oxygen evolution reaction due to their abundance and stability, and are expected to replace traditional noble metal catalysts. In this paper, porous Co3O4@C nanosheets with spinel structure were synthesized by the method of high-temperature combustion, and the elements of Fe and Cr were doped into the spinel structure of Co3O4 to improve the performance of the oxygen evolution reaction. Electrochemical results display that the catalytic performance of Fe and Cr-doped porous Co3O4@C nanosheets is better than that of the noble metal oxide catalyst RuO2 and achieves the overpotential of 230mV at 100mA cm−2. Meanwhile, the overpotential only increases by 13mV after 30 h of a long cycle, which indicates that this catalyst has good cycle stability. The doping with Fe and Cr elements induces the lattice distortion of Co3O4, leading to the increase of oxygen vacancies and the ratio of Co2+/Co3+, which is conducive to improving the performance of the oxygen evolution reaction. Our study shows a simple strategy for the development of highly efficient catalysts with earth-abundant elements for water electrolysis.