Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, College of Water Sciences, Beijing Normal University, Beijing, 100875, PR China.
Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology, College of Water Sciences, Beijing Normal University, Beijing, 100875, PR China.
Chemosphere. 2021 Jan;262:127955. doi: 10.1016/j.chemosphere.2020.127955. Epub 2020 Aug 19.
As common advanced oxidation processes, Fenton-like and peroxymonosulfate (PMS) processes have received enormous attention due to their high efficiency in the pollutants degradation. In this study, the Co/g-CN photocatalyst was prepared by facial calcination strategy and used to evaluate the behavior of the Co/g-CN/HO and Co/g-CN/PMS systems for norfloxacin (NOR) photocatalytic degradation under visible light irradiation. The composite photocatalysts exhibited better performance compared to that of pure g-CN due to the efficient separation of electron-hole pairs and visible light absorption. The Co/g-CN/PMS system possessed better photocatalytic performance than the Co/g-CN/HO system, where the degradation ratio of NOR and removal ratio of total organic carbon (TOC) were 96.4% and 54%, respectively, in 10 min. The photocatalytic mechanism was investigated using reactive species trapping experiments and electron spin-resonance spectroscopy (ESR). ⋅OH and SO were the dominant reaction species in the Co/g-CN/HO and Co/g-CN/PMS systems, respectively. According to the analysis of the NOR degradation path, SO could attack the C-H bond on the piperazine ring or quinolone group of NOR, which resulted in it more active and accelerating the destruction of NOR with SO and ⋅OH. The destruction of the quinolone group was the main pathway in the HO process, while the destruction of the piperazine ring was the main pathway in the PMS process. In sum, the Co/g-CN/PMS process had a higher photocatalytic activity and economic applicability.
作为常见的高级氧化工艺，芬顿类和过一硫酸盐（PMS）工艺因其在污染物降解方面的高效性而受到极大关注。本研究通过简便的煅烧策略制备了 Co/g-CN 光催化剂，并用于评估 Co/g-CN/HO 和 Co/g-CN/PMS 体系在可见光照射下用于诺氟沙星（NOR）光催化降解的行为。与纯 g-CN 相比，复合光催化剂由于电子-空穴对的有效分离和可见光吸收，表现出更好的性能。Co/g-CN/PMS 体系具有比 Co/g-CN/HO 体系更好的光催化性能，NOR 的降解率和总有机碳（TOC）的去除率分别在 10 分钟内达到 96.4%和 54%。通过使用活性物质捕获实验和电子顺磁共振光谱（ESR）研究了光催化机理。 ⋅OH 和 SO 分别是 Co/g-CN/HO 和 Co/g-CN/PMS 体系中的主要反应物质。根据 NOR 降解路径的分析，SO 可以攻击 NOR 上哌嗪环或喹诺酮基团的 C-H 键，这使得它更具活性，并通过 SO 和 ⋅OH 加速 NOR 的破坏。在 HO 过程中，喹诺酮基团的破坏是主要途径，而在 PMS 过程中，哌嗪环的破坏是主要途径。总之，Co/g-CN/PMS 工艺具有更高的光催化活性和经济适用性。
