| 过硫酸盐激活协同可见光催化降解四环素的机理和降解路径 | |
| Mechanism and pathways for degrading tetracycline via photocatalytic synergistic peroxysulfate-activated catalytic oxidation | |
| 摘要: 为了提升微污染水体中抗生素的降解效率，利用过硫酸钠(PDS)激活协同手性介孔TiO2可见光催化(PDS/vis-TiO2)对四环素(TC)进行降解。详细对比研究了以手性TiO2作为催化剂的PDS激活(PDS/TiO2)、可见光催化(vis-TiO2)和PDS/vis-TiO2三种体系中，降解污染物的活性物种和污染物降解路径等的差异。结果表明，不对称的螺旋堆积结构在手性介孔TiO2中引入了丰富的Ti3+，不仅提升了其可见光响应，同时能够激活PDS生成自由基。PDS/vis-TiO2体系中光生空穴h+和·OH等多种自由基可以同时参与TC的降解，5 h内其对TC去除率可达到95%以上，远超PDS/TiO2体系(TC去除率为48.9%)和vis-TiO2体系(TC去除率为71.1%)。PDS加入到光催化体系中，会受到光生电子的激活而产生自由基，从而消耗光生电子，提升光生空穴和电子的分离率，达到协同增强污染物的降解能力。另外PDS激活后产生自由基也会大大增加体系对TC的降解性能。密度泛函理论计算和中间产物分析结果表明，TC在PDS/vis-TiO2体系中的降解路径包含了光生空穴h+攻击TC的降解路径，同时也包括自由基攻击TC的降解路径。 | |
| 关键词: 手性介孔TiO2 可见光催化 过硫酸盐激活 四环素 降解路径 | |
| 基金项目: 国家自然科学基金(No.21776250)和浙江省自然科学基金(No.LY19B060004，LY20B060001)资助。 | |
| Abstract: Aiming at enhancing the degradation efficiency of antibiotics in slightly polluted water bodies, the photo- catalytic synergistic sodium peroxysulfate (PDS)-activated catalytic oxidation using chiral mesoporous TiO2 under irradiation of visible light (PDS/vis-TiO2) was employed to degrade tetracycline (TC). The differences in active species and degradation pathways of PDS activation (PDS/TiO2), visible light photocatalysis (vis-TiO2), and PDS/vis- TiO2 systems using mesoporous TiO2 as catalysts for TC degradation were comparatively studied. The results showed that the asymmetric helical stacking structure introduced abundant Ti3+ into chiral mesoporous TiO2, not only improving its visible light response but also activating PDS by Ti3+/Ti4+ couples to form free radicals. Both the photo- generated holes h+ and the free radicals (like ·OH) in the PDS/vis-TiO2 system could simultaneously participate in TC degradation. Within 5 h, the removal rate of TC (the concentration of TC in the solution was 5 mg·L-1) using the PDS/vis-TiO2 system could reach over 95%, far exceeding that of the PDS/TiO2 system (with a TC removal rate of 48.9%) and the vis-TiO2 system (with a TC removal rate of 71.1%). PDS/vis-TiO2 system had a high removal rate of TC in solutions with different concentrations, and the degradation all followed a first-order kinetic reaction process. Even when the initial concentration of TC reached 15 mg·L-1, the 5 h removal rate of TC by PDS/vis-TiO2 system could still reach 67.2%, which further indicated that the PDS synergistic photocatalysis had an effective ability to degrade TC. However, the removal rate of TC at low concentrations by PDS/vis-TiO2 was faster than using the same amount of TiO2 catalyst and PDS. Added PDS in the photocatalytic system would be activated by the photo-generated electrons to generate free radicals, which then consume photo-generated electrons to improve the separation rate of photo-generated holes and electrons, thus achieving synergistic enhancement on the pollutant degradation. Additionally, the free radicals after PDS activation would also enhance TC degradation. The density functional theory calculation and intermediate product analysis results indicate that the degradation pathway of TC in the PDS/vis-TiO2 system includes the degradation pathway of attacking TC by h+, as well as the degradation pathway of TC after the free radicals attack. | |
| Keywords: chiral mesoporous TiO2 visible light photocatalysis peroxysulfate activation tetracycline degradation pathway | |
| 投稿时间：2023-05-26 修订日期：2023-06-22 | |
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| 朱羽科,蒋孝佳,陈嘉奕,付小航,吴礼光,王挺.过硫酸盐激活协同可见光催化降解四环素的机理和降解路径[J].无机化学学报,2023,39(10):1857-1868. | |
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| Support information: 相关附件： 20230208_Supporting_Information.docx | |
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