论文标题
由2d Janus Mosse过渡金属二甲元基介导的有效电催化H2进化
Efficient Electrocatalytic H2 Evolution Mediated by 2D Janus MoSSe Transition Metal Dichalcogenide
论文作者
论文摘要
最近，具有不对称电子结构的2D JTMD邀请人们对现代科学和技术产生强烈的研究兴趣。使用第一个原理的周期性混合分散校正的密度函数理论（DFT-D）方法，我们研究了2D单层MOSSE JTMD的平衡结构，几何和电子性能，具有用于H2进化反应的电催化活性（HER）。我们已经进行了非周期性量子机械DFT计算，以找出她在2d Janus Mosse材料（即在Mo-Edges和S-或S-或S-或Seedges上）裸露的表面上最有利的途径。为了探索她的机制，反应途径和屏障的电催化性，我们考虑了群集模型系统MO10S12SE9，以说明2D单层Mosse材料的Mo-Edges和S-或S-或S-或SE-EDGES。本研究表明，Volmer-Heyrovsky反应机制是在SE终止的Mo-Edges上进化H2的热力学有利反应途径。发现在SE终止的Mo-Edges Heyrovsky反应期间的自由能屏障的变化约为3.93-7.10 kcal.mol-1（在气体和溶剂相中），表明她的激活壁层最低。这项研究表明，由于2d Janus Mosse材料的含量较低，因为H-mogration反应步骤的HOMO和LUMO过渡状态TS1出现在Mo Atoms的S-轨道和Mo原子的D-轨道的重叠。在她的速率限制步骤中，原子轨道的稳定性更好，即H迁移TS1反应步骤（在溶剂相中）是减少反应屏障的关键，因此总体催化表明H2进化的电催化性能更好。
Recently, 2D JTMDs with asymmetric electronic structures are inviting an intense research interest in modern science and technology. Using the first principles-based periodic hybrid dispersion-corrected Density Functional Theory (DFT-D) method, we have investigated the equilibrium structure, geometry, and electronic properties of the 2D monolayer MoSSe JTMD with the electrocatalytic activities for the H2 evolution reaction (HER). We have performed non-periodic quantum mechanical DFT computations to find out the most favorable HER pathway on the exposed surfaces of the 2D Janus MoSSe material i.e., on the Mo-edges and S- or Se-edges. To explore the electrocatalytic HER mechanism, reaction pathways and barriers, we have considered a cluster model system Mo10S12Se9 to illustrate the Mo-edges and S- or Se-edges of the 2D monolayer MoSSe material. The present study reveals that the Volmer-Heyrovsky reaction mechanism is thermodynamically favorable reaction pathway to evolute H2 at the Se-terminated Mo-edges. It was found that the change of free energy barrier during the Heyrovsky reaction at the Se-terminated Mo-edges is about 3.93-7.10 kcal.mol-1 (in both the gas and the solvent phases), indicating an exceptional electrocatalyst for HER with the lowest activation barriers. This study showed that the Tafel slope (m) is lower in the case of 2D Janus MoSSe material due to the overlap of the s-orbital of the hydrogen and d-orbitals of the Mo atoms appeared in the HOMO and LUMO transition state TS1 of the H-migration reaction step. The better stabilization of the atomic orbitals in the HER rate-limiting step i.e., H-migration TS1 reaction step (in the solvent phase) is a key for reducing the reaction barrier, thus the overall catalysis indicating a better electrocatalytic performance for H2 evolution.
