Facile one-step synthesis of phosphorus-doped CoS2 as efficient electrocatalyst for hydrogen evolution reaction.

Synthesizing and designing of the hydrogen evolution reaction (HER) electrode composed of earth-abundance elements is the current research topics. Among the many discovered catalysts, cobalt disulfide has outstanding performance for HER due to its catalytic activity cobalt sites. Here, phosphorus-doped cobalt disulfide (P doped CoS 2 ) samples are successfully synthesized via simple one-step hydrothermal method. By using them as the electrocatalysts, the most efficient electrode we obtained shows the excellent electrocatalytic activity, with low overpotential of 53 mV to achieve a 10 mA/cm 2 current density, a small Tafel slope of 57 mV/dec and a high stability after 10000 cycles. First-principle calculations results indicate that phosphorus dopants could improve the electrocatalytic activity of hydrogen evolution by lowing the free energy for atomic hydrogen adsorption ( Δ G H * ) at the Co sites. Moreover, the metallic P doped CoS 2 could promote electron transfer and offers faster HER kinetics, thereby leading to better HER activity. This finding demonstrates an effective way to synthesis nonmetal doped CoS 2 catalysts via one-step hydrothermal method and further improve the HER performance of CoS 2 under the guidance of theoretical calculations. [ABSTRACT FROM AUTHOR]