Pang Xiaojuan, Yang Chenghao, Zhang Ningbo, Jiang Chenwei
School of Materials and Physics, China University of Mining & Technology, Xuzhou 221116, China.
School of Mines, China University of Mining & Technology, Xuzhou 221116, China.
Int J Mol Sci. 2025 May 9;26(10):4549. doi: 10.3390/ijms26104549.
Recent research on the use of heptazine-based polymeric carbon nitride materials as potential photocatalysts for hydrogen evolution has made significant progress. However, the impact of the water cluster's size on the time-dependent photochemical mechanisms during the water splitting process of heptazine-water clusters remains largely unexplored. Here, we present a Landau-Zener trajectory surface hopping dynamics calculation for heptazine-(HO) clusters at the ADC(2) level. The electron-driven proton transfer (EDPT) mechanism reaction from water to hydrogen-bonded heptazine-water clusters was confirmed using this method, yielding a heptazinyl radical and an OH biradical as products. The calculated quantum yield of the EDPT for the heptazine-(HO) complex was 6.5%, which was slightly lower than that of the heptazine-HO complex (9%), suggesting that increasing the water cluster size does not significantly enhance the efficiency of hydrogen transfer. Interestingly, our results show that the de-excitation of the heptazine-water complex from the excited state to the ground state via the EDPT process follows both fast and slow decay modes, which govern population relaxation and facilitate the photochemical water splitting reaction. This newly identified differential decay behavior offers valuable insights that could help deepen our understanding of the EDPT process, potentially improving the efficiency of water splitting under sunlight.
近期关于使用基于七嗪的聚合氮化碳材料作为析氢潜在光催化剂的研究取得了重大进展。然而，在七嗪 - 水团簇的水分解过程中，水团簇大小对随时间变化的光化学机制的影响在很大程度上仍未得到探索。在此，我们在ADC(2)水平上对七嗪-(HO)团簇进行了朗道 - 齐纳轨迹表面跳跃动力学计算。使用该方法证实了从水到氢键合的七嗪 - 水团簇的电子驱动质子转移(EDPT)机制反应，生成七嗪基自由基和OH双自由基作为产物。七嗪-(HO)络合物的EDPT计算量子产率为6.5%，略低于七嗪 - HO络合物(9%)，这表明增加水团簇大小并不会显著提高氢转移效率。有趣的是，我们的结果表明，七嗪 - 水络合物通过EDPT过程从激发态到基态的去激发遵循快速和慢速衰减模式，这些模式控制着布居弛豫并促进光化学水分解反应。这种新发现的差异衰减行为提供了有价值的见解，有助于加深我们对EDPT过程的理解，可能提高阳光下的水分解效率。
