Enhancing efficiency of the ternary tri-chalcogenide MnPSe3 towards hydrogen evolution reaction by activating its basal plane

Feasibility of activating the basal planes of a ternary tri-chalcogenide material MnPSe3 towards hydrogen evolution reaction (HER) by internal regulation of substitutional doping is studied using first-principles electronic structure calculations. A fraction of the Mn atoms is replaced by a first– or second–row transition metal atom. While the basal plane of the pristine material is inactive to HER with the change in H adsorption free energy (ΔGH∗) of 1.41 eV, some dopants significantly improve the activity of the planes as deduced from the calculated ΔGH∗ value. Whether such substitutional doping is energetically favored is checked by calculating the formation energy of each of the materials. Activity enhancement at different concentrations of the dopants is also tested. We find that three elements, Sc, Y, and Mo, out of a total of 19, activate the basal planes with ΔGH∗ values of 0.24, 0.18, and 0.23 eV, respectively, raising the possibility of increasing the efficiency of MnPSe3 as an HER catalyst. We also find an interesting correlation between the electronic densities of states of material and the calculated ΔGH∗ values.