Heterogeneous Co-based materials are well-known for their exceptional catalytic properties in activating peroxymonosulfate (PMS) for the degradation of antibiotic pollutants. However, the potential applications of these materials are often hindered by significant Co nanoparticle aggregation and ion leaching. In this study, a carbon quantum dot-mediated self-assembly strategy was used to fabricate three-dimensional porous sponge-like Co@CDs-x (x represents the calcination tempeatures) catalysts with spatially confined Co nanoparticles. Among the samples, Co@CDs-900 exhibited a remarkable 97.8 % removal efficiency of TC in 11 minutes, with an apparent rate constant of 0.313 min. The exceptional performance of Co@CDs-900/PMS can be attributed to its large specific surface area, unique porosity, and abundant catalytically active sites, which generate ample reactive oxygen species for TC degradation. The catalyst demonstrated good degradation capabilities across a wide pH range of 3–11 and various organic pollutants such as tetranitrophenol, oxytetracycline, ciprofloxacin, methyl orange, and rhodamine B. Moreover, Co@CDs-900 maintained high activity even after the 5th cycle due to its magnetic property and spatial confinement effect, preventing catalyst loss and ion leaching during recycling tests. The degradation mechanism involved both free-radical and non-free radical pathways, with SO and O identified as the primary reactive oxygen species. The degradation intermediates of TC were identified and a plausible degradation pathway was proposed. Toxicity assessment revealed that the Co@CDs-900/PMS system effectively reduced the toxicity of TC post-degradation. This study presents an effective approach for developing sponge-like CDs assemblies with spatially confined metal nanoparticles for activating PMS in antibiotic degradation.

中文翻译：

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碳量子点组件与空间受限的钴纳米粒子集成，通过过一硫酸盐活化降解抗生素


多相钴基材料以其在激活过一硫酸盐（PMS）降解抗生素污染物方面的卓越催化性能而闻名。然而，这些材料的潜在应用常常受到显着的钴纳米颗粒聚集和离子浸出的阻碍。在这项研究中，采用碳量子点介导的自组装策略来制造具有空间限制的Co纳米粒子的三维多孔海绵状Co@CDs-x（x代表煅烧温度）催化剂。其中，Co@CDs-900 在 11 分钟内表现出 97.8% 的 TC 去除效率，表观速率常数为 0.313 分钟。 Co@CDs-900/PMS的卓越性能归因于其较大的比表面积、独特的孔隙率和丰富的催化活性位点，可产生充足的活性氧用于TC降解。该催化剂在3-11的广泛pH范围内和各种有机污染物（如四硝基苯酚、土霉素、环丙沙星、甲基橙和罗丹明B）表现出良好的降解能力。此外，Co@CDs-900即使在第5次循环后仍保持高活性，这是由于其磁性和空间限制效应，防止回收测试过程中催化剂损失和离子浸出。降解机制涉及自由基和非自由基途径，其中 SO 和 O 被确定为主要活性氧。鉴定了 TC 的降解中间体并提出了一条合理的降解途径。毒性评估表明Co@CDs-900/PMS系统有效降低了TC降解后的毒性。 这项研究提出了一种开发具有空间限制的金属纳米粒子的海绵状 CD 组件的有效方法，用于激活抗生素降解中的 PMS。