Nitrogen-doped carbon armored Cobalt oxide hollow nanocubes electrochemically anchored on fluorine-doped tin oxide substrate for acidic oxygen evolution reaction.

Developments of non-precious metal based active and stable catalysts are of great importance and challenge to green hydrogen production from acidic electrocatalytic water splitting. Design of composite catalysts with synergy between active and stable components proves to be a promising approach. Herein, N-doped carbon armored CoO hollow nanocubes electrochemically anchored on fluorine-doped tin oxide (FTO) substrates are developed as efficient and stable catalysts for acidic oxygen evolution reactions. CoO acts as the active component with N-doped carbon coating layer serving as the stable protection component, shielding CoO from direct attack of anodic dissolution. Electrochemical fixation offers firm holding of the composite catalyst onto acid-tolerant FTO substrates and hollow nanocubes serve as nano-reactors for confined fast reactions. Under optimal conditions, the composite catalyst achieves an overpotential of 465 mV at 10 mA cm in 0.5 M HSO, and stays stable for 12 hr with a 10% increment in applied potentials.