School of Environmental and Chemical Engineering, Foshan University, Foshan, 528225, China.
School of Environmental and Chemical Engineering, Foshan University, Foshan, 528225, China; Xinjiang Institute of Technology, Xinjiang, 735400, China.
Environ Pollut. 2024 Jun 15;351:124083. doi: 10.1016/j.envpol.2024.124083. Epub 2024 Apr 30.
Widespread use of tetracycline (TC) results in its persistent residue and bioaccumulation in aquatic environments, posing a high toxicity to non-target organisms. In this study, a bimetal-doped composite material AgPO/MIL-101(Fe,Cu) has been designed for the treatment of TC in aqueous solutions. As the molar ratio of Fe/Cu in composite is 1:1, the obtained material AP/MFeCu is placed in an aqueous environment under visible light irradiation in the presence of 3 mM peroxydisulfate (PDS), which forms a photo-Fenton-like catalytic system that can completely degrade TC (10 mg/L) within 60 min. Further, the degradation rate constant (0.0668 min) is 5.66 and 7.34 times higher than that of AP/MFe and AP/MCu, respectively, demonstrating a significant advantage over single metal-doped catalysts. DFT calculations confirm the strong adsorption capacity and activation advantage of PDS on the composite surface. Therefore, the continuous photogenerated electrons (e) accelerate the activation of PDS and the production of SO, resulting in the stripping of abundant photogenerated h for TC oxidation. Meanwhile, the internal circulation of Fe/Fe and Cu/Cu in composite also greatly enhances the photo-Fenton-like catalytic stability. According to the competitive dynamic experiments, SO have the greatest contribution to TC degradation (58.93%), followed by O (23.80%). The degradation intermediates (products) identified by high-performance liquid chromatography-mass spectrometry (HPLC/MS) technique indicate the involvement of various processes in TC degradation, such as dehydroxylation, deamination, N-demethylation, and ring opening. Furthermore, as the reaction proceeds, the toxicity of the intermediates produced during TC degradation gradually decreases, which can ensure the safety of the aquatic ecosystem. Overall, this work reveals the synergy mechanism of PDS catalysis and photocatalysis, as well as provides technical support for removal of TC-contaminated wastewater.
四环素（TC）的广泛使用导致其在水环境中持续残留和生物积累，对非靶标生物具有很高的毒性。在这项研究中，设计了一种双金属掺杂复合材料 AgPO/MIL-101(Fe,Cu) 用于处理水溶液中的 TC。当复合材料中 Fe/Cu 的摩尔比为 1:1 时，所得到的材料 AP/MFeCu 在可见光照射下放置在含有 3 mM 过二硫酸盐（PDS）的水环境中，形成一个类光芬顿催化体系，可在 60 分钟内完全降解 TC（10 mg/L）。此外，降解速率常数（0.0668 min）分别比 AP/MFe 和 AP/MCu 高 5.66 和 7.34 倍，显示出比单金属掺杂催化剂的显著优势。DFT 计算证实了 PDS 在复合材料表面的强吸附能力和活化优势。因此，连续的光生电子（e）加速了 PDS 的活化和 SO 的生成，导致大量光生 h 用于 TC 氧化的剥离。同时，复合材料中 Fe/Fe 和 Cu/Cu 的内部循环也极大地增强了类光芬顿催化稳定性。根据竞争动力学实验，SO 对 TC 降解的贡献最大（58.93%），其次是 O（23.80%）。高效液相色谱-质谱联用（HPLC/MS）技术鉴定的降解中间产物（产物）表明 TC 降解涉及各种过程，如脱羟、脱氨、N-去甲基化和开环。此外，随着反应的进行，TC 降解过程中产生的中间产物的毒性逐渐降低，这可以确保水生态系统的安全。总体而言，这项工作揭示了 PDS 催化和光催化的协同机制，并为去除 TC 污染废水提供了技术支持。
