Transition metal doping activated basal-plane catalytic activity of two-dimensional 1T’-ReS2 for hydrogen evolution reaction: a first-principles calculation study

Abstract

The two-dimensional 1T′ phase of ReS₂ has a unique structure and its electronic properties are independent of its thickness. These features distinguish ReS₂ from other two-dimensional transition metal dichalcogenides (TMDCs) used as catalysts in the hydrogen evolution reaction (HER) and suggest that it may be a suitable alternative catalyst to the expensive Pt most commonly in this reaction. Similar to traditional TMDCs, the catalytic activity of ReS₂ is mainly contributed by the edge sites, whereas the basal plane, which accounts for a large percentage of the surface area, has poor catalytic activity. Activation of the basal plane of ReS₂ would be an ideal strategy by which to boost its catalytic performance. We used density functional theory calculations to show that the catalytic activity of the ReS₂ basal plane can be efficiently activated by doping with transition metal (TM) atoms such as Mo, Cr, Mn, Fe, Co, Pt, Au and Ag. Our results indicate that doping with a TM not only significantly reduces the hydrogen adsorption free energy (ΔG_H*) of ReS₂ by tuning the adsorption behavior of the H atom on the ReS₂ surface, but can also expose more active sites by introducing more unsaturated electrons. Pt-doped ReS₂ showed the highest catalytic activity for the HER of all the TM-doped ReS₂ systems investigated, with ΔG_H* = 0, a low reaction barrier and an increased density of active sites on the basal plane. More importantly, ReS₂ doped with the non-noble TMs Mo and Cr showed excellent HER catalytic activities comparable with those of Pt-doped ReS₂. Our findings will help to guide the future design of new HER catalysts based on TMDCs.