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

Cobalt sulfide/sulfur doped carbon composites (Co 9 S 8 /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 Co 9 S 8 nanoparticles were clearly obtained and combined with the thin sulfur doped carbon layers. Electrochemical data showed that Co 9 S 8 /S‐C had a good activity and long‐term stability in catalyzing oxygen evolution reaction in alkaline electrolyte, even better than the traditional RuO 2 electrocatalyst. The excellent electrocatalytic activity of Co 9 S 8 /S‐C was mainly attributed to the synergistic effect between the Co 9 S 8 catalyst which contributed to the oxygen evolution reaction and the sulfur doped carbon layer which facilitated the adsorption of reactants, prevented the Co 9 S 8 particles from aggregating and served as the electrically conductive binder between each component.