In this work, iron-rich red mud (RM), a industrial waste generated from alumina production by Bayer process, was used as a potential carrier for supporting Co₃O₄ quantum dots (QDs). A novel heterogeneous catalyst of RM-based Co₃O₄ QDs (Co₃O₄/RM) composite was prepared via a simple method and used for the activation of peroxymonosulfate (PMS) under visible light (Vis) to degrade levofloxacin (LVF). The characterization results demonstrated that in-situ growth of Co₃O₄ QDs on the surface of RM could increase the surface area, reduce the aggregation, enhance the visible light response and accelerate the separation of photogenerated electron-hole pairs, all of which effectively improved the catalytic activity of Co₃O₄/RM composite. Approximately 95.3 % of LVF was decomposed at 20 min in the PMS/Vis system catalyzed by the optimal Co₃O₄/RM-1200 composite. Both SO₄·^- and h⁺ generated in Co₃O₄/RM-1200/PMS/Vis system were responsible for the rapid LVF degradation; especially the SO₄·^- was the dominant active specie. Based on LC-MS technology and DFT calculation, the reasonable degradation pathways of LVF in Co₃O₄/RM-1200/PMS/Vis system were proposed. The ecotoxicity of degradation intermediates was evaluated according to the Toxicity Estimation Software Tool (T.E.S.T.) software. In addition, critical influencing factors on the degradation of LVF in Co₃O₄/RM-1200/PMS/Vis system were investigated. Exhilaratingly, it was found that the Co₃O₄ QDs were deposited homogeneously on the surface of RM with the Fe-O-Co bond between Co₃O₄ component and Fe₂O₃ component, which not only prevented the leaching of metal ions but also contributed to the superior stability and reusability. This work has designed a new perspective for the development of a cost-efficiency and stable RM-based Co₃O₄ QDs catalyst to activate PMS under visible light for the degradation of LVF.

在这项工作中，富铁赤泥（RM）是拜耳法生产氧化铝产生的工业废料，被用作负载Co ₃ O ₄量子点（QD）的潜在载体。采用简单的方法制备了一种新型的RM基Co ₃ O ₄ QDs（Co ₃ O ₄ /RM）复合材料多相催化剂，并用于可见光（Vis）下过氧单硫酸盐（PMS）的活化降解左氧氟沙星（LVF） . 表征结果表明，Co ₃ O _{4的原位生长}RM表面的QDs可以增加表面积，减少聚集，增强可见光响应，加速光生电子-空穴对的分离，有效提高Co ₃ O ₄ /RM复合材料的催化活性。_{在最佳 Co 3} O ₄ /RM-1200 复合材料催化的 PMS/Vis 系统中，大约 95.3% 的 LVF 在 20 分钟内分解。Co ₃ O ₄ /RM-1200/PMS/Vis体系中产生的SO ₄ · ^-和h ⁺都是LVF快速降解的原因；特别是 SO ₄ · ^-是主要的活性物种。基于LC-MS技术和DFT计算，提出了LVF在Co ₃ O ₄ /RM-1200/PMS/Vis体系中的合理降解途径。根据毒性估计软件工具（TEST）软件评估降解中间体的生态毒性。此外，研究了Co ₃ O ₄ /RM-1200/PMS/Vis体系中LVF降解的关键影响因素。令人兴奋的是，发现 Co ₃ O ₄量子点均匀地沉积在 RM 表面，Co ₃ O ₄组分和 Fe ₂ O _{3之间的 Fe-O-Co 键}成分，不仅可以防止金属离子的浸出，而且还有助于提高稳定性和可重复使用性。这项工作为开发具有成本效益且稳定的RM基Co ₃ O ₄ QDs催化剂在可见光下激活PMS以降解LVF提供了新的视角。