3R TaS2 Surpasses the Corresponding 1T and 2H Phases for the Hydrogen Evolution Reaction

Abstract

We prepared new two-dimensional 3R TaS2 nanomaterials and investigated their application in hydrogen evolution reaction (HER) under acidic condition for the first time. The partial orientation aligned 3R TaS2 nanosheets show excellent electrocatalytic performance toward HER and outperform the corresponding 1T and 2H TaS2. Benefiting from the broken inversion symmetry and large exposed edge sites, the obtained 3R TaS2 nanomaterial exhibits optimized electrocatalytic activity for HER with onset overpotential as low as 106 mV, low Tafel slope of 85 mV decade–1 and high current density of 10 mA cm–2 at η = 196 mV. First-principles calculations suggest that the 3R TaS2 has more adsorption energies than 1T and 2H TaS2, confirming that the polymorph structures of TaS2 do influence their HER electrocatalytic performance. We expect that the control of polymorph structures can be an effective way to enhance the catalytic performance of transition-metal dichalcogenides (TMDs) in hydrogen evolution reaction and 3R Ta...