Zhang Jiahao, Kang Chen, Ren Junfeng, Chen Meina, Lin Zijing
School of Physics and Electronics, Shandong Normal University, Jinan, Shandong 250358, China.
Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Chem Phys. 2024 Sep 21;161(11). doi: 10.1063/5.0230967.
Heterojunction catalysts in the field of hydrogen evolution reaction (HER) from electrocatalytic water splitting have recently become a hot research topic. In this paper, we systematically calculated the HER catalytic performance of a MoS2/CoS2 heterojunction for the first time, considering the effect of edge sites regulation, strain and electric field. The results indicate that the MoS2/CoS2 heterojunction exhibits synergistic catalytic performance compared to MoS2 and CoS2, the HER catalytic activity of which can be improved by exposing more edge sites or regulating the S content on the edges, with an optimized ratio of 25%. Surprisingly, applying strain has a slight effect on the catalytic activity of the edge, however, an obvious effect on the basal plane. For example, applying 2% tensile strain on the MoS2/CoS2 heterojunction can improve the edge catalytic performance by 13%, and for the basal plane, this value can reach 92%. In this case, the catalytic performance of the basal plane is better than that of the edge with 2% and without strain. Since the basal plane accounts for the majority of the two-dimensional catalysts, the catalytic performance of the basal plane is generally much lower than that of the edge. This discovery is of great significance, which means by adjusting strain, the catalytic performance of the heterojunction catalyst is likely to be improved by orders of magnitude. Moreover, considering the actual experimental process, we also calculated the effect of the electric field and found that 0.7 V/Å electric field can enhance the HER catalytic activity of the MoS2/CoS2 heterojunction by 23%.
在电催化水分解析氢反应（HER）领域，异质结催化剂最近已成为一个热门研究课题。在本文中，我们首次系统地计算了MoS2/CoS2异质结的析氢催化性能，考虑了边缘位点调控、应变和电场的影响。结果表明，与MoS2和CoS2相比，MoS2/CoS2异质结表现出协同催化性能，通过暴露更多边缘位点或调控边缘上的硫含量，其析氢催化活性可以得到提高，优化比例为25%。令人惊讶的是，施加应变对边缘的催化活性影响较小，然而，对基面有明显影响。例如，在MoS2/CoS2异质结上施加2%的拉伸应变可使边缘催化性能提高13%，而对于基面，该值可达到92%。在这种情况下，施加2%应变且无应变时基面的催化性能优于边缘。由于基面占二维催化剂的大部分，基面的催化性能通常远低于边缘。这一发现具有重要意义，这意味着通过调整应变，异质结催化剂的催化性能可能会提高几个数量级。此外，考虑到实际实验过程，我们还计算了电场的影响，发现0.7 V/Å的电场可使MoS2/CoS2异质结的析氢催化活性提高23%。
