Nitrogen-Doped Cobalt Oxide Nanostructures Derived from Cobalt-Alanine Complexes for High-Performance Oxygen Evolution Reactions

Taking advantage of the self-assembling function of amino acids, cobalt-alanine complexes are synthesized by straightforward process of chemical precipitation. Through a controllable calcination of the cobalt-alanine complexes, N-doped Co3O4 nanostructures (N-Co3O4) and N-doped CoO composites with amorphous carbon (N-CoO/C) are obtained. These N-doped cobalt oxide materials with novel porous nanostructures and minimal oxygen vacancies show a high and stable activity for the oxygen evolution reaction. Moreover, the influence of calcination temperature, electrolyte concentration, and electrode substrate to the reaction are compared and analyzed. The results of experiments and density functional theory calculations demonstrate that N-doping promotes the catalytic activity through improving electronic conductivity, increasing OH- adsorption strength, and accelerating reaction kinetics. Using a simple synthetic strategy, N-Co3O4 reserves the structural advantages of micro/nanostructured complexes, showing exciting potential as a catalyst for the oxygen evolution reaction with good stability.