Janus MoSSe纳米带析氢催化活性研究

In recent years, Janus transition metal dihalides (TMDS) have become a hot topic in electrocatalysis due to their unique asymmetric properties.Based on density functional theory, the catalytic activity of single-layer Janus MoSSe nanoribbons (straight MoSSe_Stress, MoSSe_NoStress model and curled MoSSe_Bent model) under three different stress conditions along the two directions of Armhair and Zigzag for hydrogen evolution reaction has been systematically studied in this paper.The calculated results show that the bond length and bond angle of the optimized MoSSe_Stress, MoSSe_NoStress and MoSSe_BentJanus MoSSe single-layer nanoribbons differ due to different degrees of stress release in the structure. The Mo-S bond length is generally shorter than the Mo-Se bond length in both Armchair and Zigzag directions.In the case of curled MoSSe_Bent, the bond length difference between Mo-Se and Mo-S reaches the largest, with the largest bending Angle (81.007deg).It was found that, similar to common TMDS materials, the original Janus MoSSe single-layer nanoribbon has catalytic inerty on its base surface, which is improved after the introduction of low concentration of S\Se defects, which activate the catalytic performance of the nanoribbon base surface, and the formation energy of all defects is between 2.375~3.437eV/ A. These results indicate that these defects can be easily introduced into Janus MoSSe nanoribbon.For all cases of nanoribbon, the ?GH value of all adsorption sites along the Amchair direction is between 1.242 and 2.321eV, and the ?GH value of all adsorption sites along the Zigzag direction is between 0.98 and 1.73eV. The nanoribbons along the Zigzag direction showed better catalytic performance.After introducing a certain concentration of defects, the value of ?GH in the Amchair direction is between -0.264~0.363eV, and that in the Zigzag direction is between -0.309~-0.516eV, so the hydrogen evolution performance of the nanoribbon along the Armchair direction is more excellent.In particular, Bent_MoSSe nanoribbon has better hydrogen evolution performance among the nanoribbon models under three different conditions. When Se defect is introduced into Bent_MoSSe nanoribbon along the Amchair direction, the ?GH value can reach -0.264eV, which has the best hydrogen evolution performance.