In this study, cobalt-encapsulated nitrogen-doped carbon hollow nanospheres (Co@NCs) were synthesized for peroxymonosulfate (PMS) activation and tetracycline (TC) degradation. Co@NCs synthesized at a high pyrolysis temperature exhibited relatively higher graphitic N and C═C contents, which effectively regulated the electron density of Co sites, enhancing the PMS activation efficiency. In the Co@NCs-900/PMS system, remarkable TC removal efficiency (97.14%, k_obs = 0.179 min^-1) and TOC removal (63.62%) were achieved within 60 min. Based on the quenching tests, EPR technology, and electrochemical measurements, a synergistic radical and nonradical pathway was unveiled, with SO₄^•-, ¹O₂, and ETP dominated. Co@NCs-900/PMS showed efficient catalytic performance and practical application potentials without interference from organic and inorganic compounds under the experimental background. Additionally, over 80% TC removal could be achieved after the seven-cycle catalytic reaction and showed negligible Co²⁺ leaching, indicating superior recyclability. Chemical analysis and DFT calculation revealed that PMS adsorption and activation could be strengthened by modulating the electron density with Co and N serving as the active sites. Overall, this study provides valuable insights into the incorporation of metal sites on N-doped carbonaceous catalysts for Fenton-like reactions in water purification applications.

Keywords: cobalt-incorporation; electron transfer process; peroxymonosulfate; tetracycline; theoretical calculation.

在这项研究中，合成了封装钴的氮掺杂碳空心纳米球（Co@NCs），用于过一硫酸盐（PMS）活化和四环素（TC）降解。在高温裂解条件下合成的Co@NCs表现出较高的石墨氮和C=C含量，有效地调节了Co位点的电子密度，从而提高了PMS活化的效率。在Co@NCs-900/PMS体系中，在60分钟内实现了显著的TC去除率（97.14%，k_obs = 0.179 min^-1）和TOC去除率（63.62%）。基于淬灭实验、EPR技术和电化学测量，揭示了一种协同的自由基和非自由基途径，其中SO₄^•-、¹O₂ 和ETP占主导地位。Co@NCs-900/PMS在实验背景条件下表现出高效的催化性能和实际应用潜力，不受有机物和无机物的干扰。此外，在七次循环催化反应后仍能实现超过80%的TC去除率，并且几乎没有Co²⁺的浸出，表明其具有优异的可回收性。化学分析和DFT计算表明，通过调节电子密度可以增强PMS吸附和活化过程，其中Co和N作为活性位点发挥作用。总体而言，这项研究为在水净化应用中将金属位点引入氮掺杂碳基催化剂以用于类芬顿反应提供了有价值的见解。

关键词：钴嵌入；电子转移过程；过一硫酸盐；四环素；理论计算。