Catalytic activity for hydrogen evolution reaction of Janus monolayer MoXTe (X1/4S, Se)

At present, the precious metal Pt is a common catalyst for large-scale hydrogen evolution reaction (HER) production of hydrogen, but due to its high price and scarcity, finding an innovative catalyst has become the key to electrocatalytic hydrogen evolution. Here, the HER electrocatalytic activity of Janus MoXTe (X = S, Se) monolayers was investigated through first-principles calculations. Mo vacancy, X vacancy and Te vacancy were intro-duced into 2H, 1T, and 1T' phase respectively and their stability was studied. The results show that the introduction of vacancy can improve the electrocatalytic hydrogen evolution performance. Particularly, the Gibbs free energies (DGH) of Te vacancy of 2H phase MoSTe and MoSeTe are close to zero (DGH = 0.03, -0.05 eV, respectively), and has the highest exchange current density. We further find that the conductivity of 2H phase MoSTe and MoSeTe is enhanced after introducing Te vacancy. In details, H get 1.86 and 1.43 e on VTe in 2H phase MoSTe and MoSeTe. The bond between S and H is more stable, H is better adsorbed on the catalyst, and the performance is improved. Our research provides a strategy for designing MoXTe monolayer electrocatalysts, which are predicted to be employed in HER catalysts with low cost and high performance.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Currently, finding a new catalyst for electrocatalytic hydrogen evolution has become crucial due to the high price and scarcity of the precious metal Pt. In this study, the electrocatalytic activity of Janus MoXTe (X = S, Se) monolayers for hydrogen evolution reaction (HER) was investigated. By introducing vacancies, the catalytic performance was improved, especially with Te vacancies in 2H phase MoSTe and MoSeTe, which showed the highest exchange current density and enhanced conductivity. Our research provides a strategy for designing MoXTe monolayer electrocatalysts that are predicted to have low cost and high performance for HER.