Xu Hengtao, Hao Zhe, Feng Weihua, Wang Ting, Li Yao
Key Laboratory of Engineering Oceanography, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China.
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China.
ACS Omega. 2021 Nov 5;6(45):30698-30707. doi: 10.1021/acsomega.1c04604. eCollection 2021 Nov 16.
The mechanism of photodegradation of organic pollutants in seawater by TiO-based catalysts irradiated by visible light was first explored by adding holes and free radical traps. The results showed that the photogenerated holes formed by the catalyst played a key role in the degradation of organic pollutants, regardless of whether the photodegradation occurred in seawater or pure water. Considering that the Yb-TiO-rGO catalyst has a strong adsorption for organics, the salt ion almost did not interfere with the adsorption of pollutants by Yb-TiO-rGO. Therefore, the degradation performance of Yb-TiO-rGO did not remarkably change in the two water systems. For P25-ZN with a weak adsorption capacity for organics, several salt ions in the seawater hindered the contact of pollutants with the catalyst surface. Thus, the degradation rate of P25-ZN for phenol was significantly reduced. After the solvothermal reduction treatment for catalysts using ethylene glycol (EG) as the solvent, the increase in the Ti content in the catalyst improved the visible-light response and activity of the catalyst. In addition, a small amount of EG grafted on the catalyst surface promoted the photocatalytic reaction process on the catalyst surface, thereby effectively resisting the interference of salt ions.
通过添加空穴和自由基捕获剂，首次探索了可见光照射下TiO基催化剂对海水中有机污染物的光降解机理。结果表明，无论光降解发生在海水还是纯水中，催化剂产生的光生空穴在有机污染物的降解中都起着关键作用。考虑到Yb-TiO-rGO催化剂对有机物有较强的吸附作用，盐离子几乎不干扰Yb-TiO-rGO对污染物的吸附。因此，Yb-TiO-rGO在两种水体系中的降解性能没有明显变化。对于对有机物吸附能力较弱的P25-ZN，海水中的几种盐离子阻碍了污染物与催化剂表面的接触。因此，P25-ZN对苯酚的降解率显著降低。以乙二醇（EG）为溶剂对催化剂进行溶剂热还原处理后，催化剂中Ti含量的增加提高了催化剂的可见光响应和活性。此外，催化剂表面接枝的少量EG促进了催化剂表面的光催化反应过程，从而有效抵抗盐离子的干扰。
