Yuan Shaoyu, Chen Min, Qin Xiaoxiao, Chen Xueyan, Zhang Jianghao, Zhang Changbin
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Environ Sci (China). 2025 Jan;147:561-570. doi: 10.1016/j.jes.2023.04.035. Epub 2023 May 8.
In the present study, we investigated the influence of surface fluorine (F) on TiO for the photocatalytic oxidation (PCO) of toluene. TiO modified with different F content was prepared and tested. It was found that with the increasing of F content, the toluene conversion rate first increased and then decreased. However, CO mineralization efficiency showed the opposite trend. Based on the characterizations, we revealed that F substitutes the surface hydroxyl of TiO to form the structure of Ti-F. The presence of the appropriate amount of surface Ti-F on TiO greatly enhanced the separation of photogenerated carriers, which facilitated the generation of ·OH and promoted the activity for the PCO of toluene. It was further revealed that the increase of only ·OH promoted the conversion of toluene to ring-containing intermediates, causing the accumulation of intermediates and then conversely inhibited the ·OH generation, which led to the decrease of the CO mineralization efficiency. The above results could provide guidance for the rational design of photocatalysts for toluene oxidation.
在本研究中，我们研究了表面氟（F）对用于甲苯光催化氧化（PCO）的TiO的影响。制备并测试了用不同氟含量改性的TiO。结果发现，随着氟含量的增加，甲苯转化率先升高后降低。然而，CO矿化效率呈现相反的趋势。基于表征，我们揭示氟取代了TiO的表面羟基以形成Ti-F结构。TiO上适量表面Ti-F的存在极大地增强了光生载流子的分离，这促进了·OH的生成并提高了甲苯PCO的活性。进一步揭示，仅·OH的增加促进了甲苯向含环中间体的转化，导致中间体的积累，进而反过来抑制·OH的生成，这导致了CO矿化效率的降低。上述结果可为合理设计用于甲苯氧化的光催化剂提供指导。
