Defect engineered Janus MoXTe (X1/4S, Se) monolayers for hydrogen evolution reaction: A first principles study

Given the elevated expense and constrained accessibility of platinum, the primary catalyst employed in electrocatalytic hydrogen evolution, it becomes essential to pinpoint an alternative catalyst demonstrating exceptional catalytic efficacy and broader scalability potential. In this study, we undertook an exhaustive inquiry into the electrocatalytic activity concerning hydrogen evolution of the monolayer Janus MoXTe (where X represents S and Se) utilizing first-principle calculation. Furthermore, an evaluation of the performance of defective MoXTe structures was conducted. Our findings illuminate that the incorporation of non-metallic elements like B, C, N, and P into MoXTe can be employed to finely adjust the Gibbs free energy (DGH) to approximately 0 eV. Particularly, the doping of B and P into the 1T phase of MoSTe (1T-MoSTe-B@ represents 1T phase of MoSTe-B@ and 1TMoSTe-P@ represents 1T phase of MoSTe-P@), the doping of P into the 1T' phase of MoSTe (1T' phase of MoSTe-P@), and the doping of P into the 1T' phase of MoSeTe (1T' phase of MoSeTe-P@) exhibit DGH values that are in close proximity to zero (DGH = 0.02, -0.03, 0.06, and -0.14 eV, respectively). Through further analysis, we found that the pristine and defective structures all exhibit metallic properties. And the doping of P improved HER performance more effectively among four nonmetallic dopants. In details, H get 0.21, 0.29, 0.43 and 0.28 e on doping of B and P into 1T phase MoSTe (1T phase of MoSTe-B@ and 1T phase of MoSTe-P@) and the doping of P into 1T' phase MoSeTe (1T' phase of MoSeTe-P@). This study provides strategies for the design of MoXTe monolayer electrocatalysts, and it is expected to be applied to HER catalysts in affordable and efficient manner.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.