Activation of efficient hydrogen evolution on 1T-VS2 nanoribbons by low-cost transition metals: A first-principles study

Abstract

Electrocatalytic water splitting is a very important energy conversion technology that utilizes renewable energy sources to produce hydrogen for sustainable energy development. In this work, the catalytic performance of 1T-VS2 (1T phase of vanadium disulfide) nanoribbons in the hydrogen evolution reaction (HER) was investigated based on first-principles calculations. It was found that 1T-VS2 nanoribbons have a Gibbs free energy (ΔGH*) of 0.05 eV, demonstrating its excellent HER performance. Moreover, some transition metal substitutions can further improve this performance (e.g. the ΔGH* of the Ti/Fe-1T-VS2 are as low as −0.02/0.04 eV). The mechanism of the performance enhancement is thoroughly investigated. The improved catalytic performance of HER is mainly promoted by hybridization between the V-d and TM-d-orbitals. The crystal orbital Hamiltonian population (COHP) and integral crystal orbital Hamiltonian habitation (ICOHP) calculations show that the HER properties are closely related to the filling of bonding and antibonding states. The differential charge density indicates that the adsorption of H results in an effective charge transfer at the interface and an increase in the conductivity, leading to an increase in the HER. The HER activity of the TM-1T-VS2 (TM stands for transition metal) nanoribbons is also related to the proximity of the adsorption site to the edge. Our work suggests that the TM-1T-VS2 nanoribbons are expected to be low cost and highly efficient catalysts.