Effect of Precursor and Calcination Time on the Morphological Structure and Catalytic Activity of Co3O4 Film in the Oxygen Evolution Reaction

This research investigates the effect of cobalt precursor and calcination time on the morphology and catalytic activity of Co3O4 films in the oxygen evolution reaction (OER). Co3O4 films with porous flower-like nanostructures were obtained using cobalt nitrate as a cobalt precursor, while cobalt chlorides were used to produce porous nanoneedle structures Co3O4 film. Extended annealing time at temperatures 350°C caused structural fractures in the films. Among the samples, the synthesized Co3O4 films were then evaluated as catalyst materials for the OER in alkaline 1M KOH electrolyte. Among synthesized films, the Co3O4-2-1h, synthesized using the cobalt chlorides as Co precursor and annealed at 350°C for 1 hour, exhibited better OER catalytic activity. With its porous nanoneedle structure, the Co3O4-2-1h demonstrated superior performance comparable to the state-of-the-art 20% Ir/C catalyst. Moreover, the Co3O4-2-1h film demonstrates remarkable stability for the OER in a 1M KOH alkaline electrolyte.