Department of Theoretical, Atomic and Optical Physics, University of Valladolid, 47011 Valladolid, Spain.
The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34151 Trieste, Italy.
Molecules. 2023 Jul 3;28(13):5182. doi: 10.3390/molecules28135182.
Density functional theory (DFT) calculations are employed to study the oxygen evolution reaction (OER) on the edges of stripes of monolayer molybdenum disulfide. Experimentally, this material has been shown to evolve oxygen, albeit with low efficiency. Previous DFT studies have traced this low catalytic performance to the unfavourable adsorption energies of some reaction intermediates on the MoS edge sites. In this work, we study the effects of the aqueous liquid surrounding the active sites. A computational approach is used, where the solvent is modeled as a continuous medium providing a dielectric embedding of the catalyst and the reaction intermediates. A description at this level of theory can have a profound impact on the studied reactions: the calculated overpotential for the OER is lowered from 1.15 eV to 0.77 eV. It is shown that such variations in the reaction energetics are linked to the polar nature of the adsorbed intermediates, which leads to changes in the calculated electronic charge density when surrounded by water. These results underline the necessity to computationally account for solvation effects, especially in aqueous environments and when highly polar intermediates are present.
密度泛函理论（DFT）计算被用于研究单层二硫化钼条带边缘的氧气析出反应（OER）。实验表明，这种材料能够释放氧气，尽管效率较低。先前的 DFT 研究表明，这种低催化性能可归因于某些反应中间体在 MoS 边缘位置的不利吸附能。在这项工作中，我们研究了活性位点周围水溶液的影响。我们使用了一种计算方法，其中将溶剂建模为连续介质，为催化剂和反应中间体提供介电嵌入。在这种理论水平上的描述可以对研究的反应产生深远的影响：OER 的过电势从 1.15eV 降低到 0.77eV。结果表明，这种反应能量学的变化与吸附中间体的极性有关，当被水包围时，这会导致计算出的电子电荷密度发生变化。这些结果强调了在计算中考虑溶剂化效应的必要性，特别是在水相环境中和存在高极性中间体时。
