Efficient Hydrogen Evolution on Cu Nanodots-Decorated Ni_3S_2 Nanotubes by Optimizing Atomic Hydrogen Adsorption and Desorption

摘要

Low-cost transition-metal dichalcogenides (MS_(2)) have attracted great interest as alternative catalysts for hydrogen evolution. However, a significant challenge is the formation of sulfur–hydrogen bonds on MS_(2) (S–H_(ads)), which will severely suppress hydrogen evolution reaction (HER). Here we report Cu nanodots (NDs)-decorated Ni_(3)S_(2) nanotubes (NTs) supported on carbon fibers (CFs) (Cu NDs/Ni_(3)S_(2) NTs-CFs) as efficient electrocatalysts for HER in alkaline media. The electronic interactions between Cu and Ni_(3)S_(2) result in Cu NDs that are positively charged and can promote water adsorption and activation. Meanwhile, Ni_(3)S_(2) NTs are negatively charged and can weaken S–H_(ads) bonds formed on catalyst surfaces. Therefore, the Cu/Ni_(3)S_(2) hybrids can optimize H adsorption and desorption on electrocatalysts and can promote both Volmer and Heyrovsky steps of HER. The strong interactions between Cu and Ni_(3)S_(2) cause the Cu NDs/Ni_(3)S_(2) NTs-CFs electrocatalysts to exhibit the outstanding HER catalytic performance with low onset potential, high catalytic activity, and excellent stability.