Engineering Active Sites of 2D Materials for Active Hydrogen Evolution Reaction

Hydrogen evolution reaction (HER) is a promising clean and sustainable energy source with zero carbon emissions. Numerous studies have been conducted with versatile low dimensional materials, and the development of highly active electrochemical catalysts for HER is one of the most important applications of the materials in these studies. Despite such extensive research, the physical origin of the active catalytic performance of low dimensional materials remains unclear, and is distinguished from that of classical transition metal-based catalysts. Here, recent studies on the intrinsic catalytic activity of 2D semimetals are reviewed, particularly among transition metal dichalcogenides (TMDs), highlighting promising strategies for the design of materials to further enhance their catalytic performance. One attractive approach for active HER involves fabricating single-atom catalysts in the framework of TMDs. The electrochemical reaction at a catalytic atom for hydrogen evolution has typically been described by the Sabatier principle. Recent studies have focused on optimizing the Gibbs free energy for hydrogen adsorption via down-sizing, alloying, hybridizing, hetero-structuring, and phase boundary engineering, mostly with TMDs. The unique advantages of TMDs and their derivatives for HER are summarized, suggesting promising research directions for the design of low dimensional electrochemical catalysts for efficient HER and their energy applications. Recent studies on the intrinsic catalytic activity of 2D semimetals have been reviewed particularly from the viewpoint of the hydrogen evolution reaction. Promising strategies for materials design to further enhance catalytic performance have been suggested, focusing on downsizing, alloying, hybridizing, hetero-structuring, and phase boundary engineering approaches, mostly with transition metal dichalcogenides. image