Effective CoxSy HER Electrocatalysts Fabricated by In-Situ Sulfuration of a Metal-Organic Framework

A sulfur and nitrogen containing cobalt metal-organic framework (Co-MOF) was chosen as a precursor to prepare cobalt sulfides as HER electrocatalysts. Cobalt sulfides with different stoichiometries, CoS1.097, Co9S8, Co9S8/CoS1.097, and Co9S8/CoS1.097/rGO, were obtained through a phase control method and in-situ sulfuration of the MOF precursor. Co9S8/CoS1.097/rGO shows excellent HER performance, with an overpotential of 50 mV at a current density (j) of 1 mA cm(-2) (eta(0)), and 188 mV at a current density of 10 mA cm(-2) (eta(10)), stemming from the synergistic effect of Co9S8, CoS1.097, high specific surface area and the nitrogen and sulfur doped carbon matrix.