Enhanced Hydrogen Evolution Reaction in Surface Functionalized MoS2 Monolayers

Monolayered, semiconducting MoS2 and their transition metal dichalcogenides (TMDCs) families are promising low-cost materials for hydrogen generation through electrolytes (HER, evolution reaction) due to high activities electrochemical stability during the reaction. However, there is still a lack of understanding in identifying underlying mechanism responsible improving electrocatalytic properties theses monolayers. In this work, we investigated significance controlling carrier densities monolayer turn corresponding behaviors relation energy band structure MoS2. Surface functionalization was employed achieve p-doping n-doping that led devices with different catalytic performances. Specifically, electron-rich surface showed lower overpotential Tafel slope compared functional groups contributed p-doping. We attributed such enhancement increase density Fermi level accelerated HER charge transfer kinetics. These findings importance designing electrocatalysts based on two-dimensional TMDCs.