Synthesis of Cobalt Sulfide/Sulfur Doped Carbon Nanocomposites with Efficient Catalytic Activity in the Oxygen Evolution Reaction.

Cobalt sulfide/sulfur doped carbon composites (Co9 S8 /S-C) were synthesized by calcining a rationally designed sulfur-containing cobalt coordination complex in an inert atmosphere. From the detailed transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses, the electrocatalytically active Co9 S8 nanoparticles were clearly obtained and combined with the thin sulfur doped carbon layers. Electrochemical data showed that Co9 S8 /S-C had a good activity and long-term stability in catalyzing oxygen evolution reaction in alkaline electrolyte, even better than the traditional RuO2 electrocatalyst. The excellent electrocatalytic activity of Co9 S8 /S-C was mainly attributed to the synergistic effect between the Co9 S8 catalyst which contributed to the oxygen evolution reaction and the sulfur doped carbon layer which facilitated the adsorption of reactants, prevented the Co9 S8 particles from aggregating and served as the electrically conductive binder between each component.