Nitrogen and Sulfur Co-Doped Mesoporous Carbon Embedded with Co9 S8 Nanoparticles: Efficient Electrocatalysts for Hydrogen Evolution.

Abstract

Co9 S8 embedded, N,S co-doepd mesoporous carbon materials were synthesized by adopting CoCl2 as the molten salt. In details, CoCl2 and glucose were used as cobalt and carbon precursors, respectively, and thiourea was utilized as sulfur and nitrogen precursors. This synthetic process involved three steps, including hand-milling, carbonation, and acid leaching. The results of characterization exhibited that the final products had mesoporous structures, which also showed high nitrogen and sulfur contents. Moreover, the Co9 S8 nanoparticles dispersed evenly in the carbonaceous matrix. Furthermore, the calcining temperature could affect the porosities of the final products and the contents of the heteroatoms, which could further determine the electrocatalytic activities of these catalysts. When used as the electrocatalysts for hydrogen evolution reaction, the optimal catalyst, GTCo900, exhibited superior catalytic activities under acidic condition. The overpotential is 62 mV to afford a current density of 10 mA cm-2 . Moreover, it could also reveal excellent stability for 12 h.