Wang Lei, Liu Xiaofeng, Li Qunxiang, Yang Jinlong, Hu Wei
Department of Chemical Physics, and State Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
School of Physics, Hefei University of Technology Hefei Anhui 230009 China
Chem Sci. 2025 Aug 22. doi: 10.1039/d5sc02736e.
Rutile TiO shows great potential for photocatalytic water (HO) splitting into oxygen (O) and hydrogen peroxide (HO). However, the mechanism of surface water oxidation on rutile TiO remains unclear, involving complex ground-state thermal catalysis and excited-state photocatalysis processes. Here, by using linear response time-dependent density functional theory (LR-TDDFT), we investigate HO oxidation at both the ground-state and excited-state levels. Our results show that O formation is thermocatalytic and occurs at room temperature, while HO desorption is driven by photogenerated holes, requiring light to overcome a high-energy barrier, which agrees with experiments showing O formation is more favorable. Furthermore, comparing the computational results obtained using the local PBE and nonlocal HSE functionals, we find the HSE provides a more accurate description of the electronic interactions between TiO and the adsorbates, and the reaction pathways, especially under excited-state conditions. Our work provides a pathway for understanding TiO water oxidation mechanisms.
金红石型二氧化钛在光催化水（H₂O）分解为氧气（O₂）和过氧化氢（H₂O₂）方面显示出巨大潜力。然而，金红石型二氧化钛表面水氧化的机制仍不清楚，涉及复杂的基态热催化和激发态光催化过程。在此，通过使用线性响应含时密度泛函理论（LR - TDDFT），我们在基态和激发态水平上研究了H₂O氧化。我们的结果表明，O₂的形成是热催化的，在室温下发生，而H₂O₂的解吸由光生空穴驱动，需要光来克服高能垒，这与表明O₂形成更有利的实验结果一致。此外，比较使用局域PBE和非局域HSE泛函获得的计算结果，我们发现HSE能更准确地描述TiO₂与吸附质之间的电子相互作用以及反应途径，特别是在激发态条件下。我们的工作为理解TiO₂水氧化机制提供了一条途径。
