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Recently, chalcogenides have attracted much attention as electrocatalysts in hydrogen evolution reaction (HER). However, few studies have been conducted on the electrocatalytic properties of gallium oxides and chalcogenides. In this paper, a Ga 2 XY (X ≠ Y, X, Y=O, S, Se, Te) defect structure doped by non-metal B, C, N, P, Si, and As have been designed. According to the study, the doping of non-metal atoms can significantly enhance their HER properties, the Ga 2 OSe-As Xi -Xi structure and Ga 2 SeTe-Si Xi -NM structure possess intensely excellent HER properties in this study with the Gibbs free energy of 0.01 eV and 0.00 eV, respectively. It is found that the Ga 2 SeTe structure has a more concentrated electron transfer range compared to the Ga 2 OSe structure, leading to a superior HER performance. This work provides a new idea for the study of HER electrocatalytic performance of the Ga 2 XY system, and it is expected to be applied to HER catalysts affordably and efficiently. • Screening of non-metal doped Ga 2 XY defective structures for HER electrocatalytic performance. • The introduction of Ga vacancies significantly enhances the HER performance of Ga 2 XY structures. • The Ga 2 SeTe defective doped structure has a more concentrated electron transfer range compared to the Ga 2 OSe structure. • The As-doped Ga 2 OSe structure and the Si-doped Ga 2 SeTe structure containing Ga defect have a near-zero ΔG H. [ABSTRACT FROM AUTHOR]

Hydrogen as a sustainable and clean energy source has been widely noticed, but it is urgent to find an efficient and stable electrocatalyst to increase its hydrogen production. For the catalytic performance of electrocatalysts, defects, doping, and stress are usually selected to enhance the catalytic performance, on the basis of which in this paper, MSi 2 N 4 (M = Mo, W) system containing vacancies and bimetallic doping was constructed and analyzed for its HER performance. The results show that the formation energy of all structures is stable and Ni doping can significantly improve the stability according to formation energy of the structures with vacancy. Both ipsilateral doping and contralateral doping can significantly improve the Gibbs free energy of MA 2 Z 4 materials, especially the MoSi 2 N 4 doped with double Co. In particular, the values of Gibbs free energy of C-Ni-V N @MoSi 2 N 4 -N in and C-Co-V N @WSi 2 N 4 -N in are −0.027 eV and 0.041 eV, significantly better than the performance of the recognized electrocatalyst Pt, which has a free energy of only 0.09 eV. After doped with transition metallic atoms, the energy bands of all materials present semiconductor property. Our work provides a novel method for the regulation of MA 2 Z 4 family materials and a theoretical strategy for designing efficient HER electrocatalysts. • Screening of bimetal-doped MA 2 Z 4 with defective structures for HER catalytic activity. • The HER performance of the ipsilateral doping is better than that of the contralateral doping. • The vacancies can significantly improve the formation energy of Ni doped materials. • The MoSi 2 N 4 defect structure doped with double Co has a near-zero ΔG H. [ABSTRACT FROM AUTHOR]

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 (ΔG H) 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 1T-MoSTe-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 ΔG H values that are in close proximity to zero (ΔG H = 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. • Screening of Catalytic Activity of 1T, and 1T′ phases Janus MoXTe (X = S, Se) monolayers. • Nonmetallic atom doping can affect the interaction between H and the material surface. • The doping of B and P into the 1T phase of MoSTe, P into the 1T′ phase of MoSTe and MoSeTe can improve the conductivity. [ABSTRACT FROM AUTHOR]