A solvent-free strategy for synthesis of Co₉S₈ nanoparticles entrapped, N, S-codoped mesoporous carbon as hydrogen...

A facile solvent-free method was developed to synthesize Co₉S₈ nanoparticles entrapped, N, S-codoped mesoporous carbon, which involved two steps, including hand milling and carbonation. This synthetic route did not require any solvent during the entire process. Moreover, no water and/or acid solution were needed to remove the impurity from the calcined samples. The final products had mesoporous structures, as well as high Co, N, and S contents. In details, N and S atoms both doped into the carboneous matrix, and the Co₉S₈ nanoparticles also dispersed well in the composites. The characterization results revealed that the ratios of the precursors and the calcination temperatures both determined the porosities of the final products, which could further affect the electrocatalytic activities. The optional sample, G2.0T1.0Co0.3-900, revealed excellent electrocatalytic activities for hydrogen evolution reaction (HER) under acidic condition, requiring overpotential of 71 mV to afford a current density of 10 mA cm^-2. Additionally, G2.0T1.0Co0.3-900 also showed superior stability and duration.