单层
Atom(片上系统)
极限(数学)
基面
平面(几何)
相(物质)
金属
化学
材料科学
化学物理
结晶学
凝聚态物理
分子物理学
纳米技术
物理
数学
几何学
有机化学
计算机科学
数学分析
嵌入式系统
作者
Megha Megha,Prasenjit Sen
摘要
Layered ternary transition metal tri-chalcogenides are some of the most promising candidates for hydrogen evolution reaction (HER) because of their ease of synthesis and affordability. However, majority of the materials in this category have HER active sites only at their edges, rendering a large portion of the catalyst useless. In this work, ways for activating the basal planes of one of these materials, namely, FePSe3, are explored. The effects of substitutional transition metal doping and external biaxial tensile strain on the HER activity of the basal plane of a FePSe3 monolayer are studied via first principles electronic structure calculations based on density functional theory. This study reveals that although the basal plane of the pristine material is inactive towards HER (value of H adsorption free energy, ΔGH* = 1.41 eV), 25% Zr, Mo, and Tc doping makes it more active (ΔGH* = 0.25, 0.22 and 0.13 eV, respectively). The effect of reducing the doping concentration, moving to the single-atom limit, on the catalytic activity is studied for Sc, Y, Zr, Mo, Tc and Rh dopants. For Tc, the mixed-metal phase FeTcP2Se6 is also studied. Among the unstrained materials, 25% Tc-doped FePSe3 gives the best result. Significant tunability of HER catalytic activity in the 6.25% Sc doped FePSe3 monolayer via strain engineering is also discovered. An external tensile strain of 5% reduces ΔGH* to ∼0 eV from 1.08 eV in the unstrained material, making this an attractive candidate for HER catalysis. The Volmer-Heyrovsky and Volmer-Tafel pathways are examined for some of the systems. A fascinating correlation between the electronic density of states and HER activity is also observed in most materials.
科研通智能强力驱动
Strongly Powered by AbleSci AI