Abstract: A one-step sol-gel synthesis method was employed to fabricate cobalt-doped silica aerogel (Co@Si-A) catalysts in this study, which were subsequently applied for activating peroxymonosulfate (PMS) to degrade tetracycline (TC). The experimental results demonstrated that the catalyst with a 25wt% cobalt doping ratio (25Co@Si-A) exhibited the most superior catalytic performance, achieving an exceptionally high TC degradation efficiency of 98.97% under the specified test conditions. Brunauer-Emmett-Teller (BET) analysis revealed that the 25Co@Si-A catalyst possessed a high specific surface area and a well-developed porous architecture rich in nano-confined spaces. The synergistic 25Co@Si-A/PMS system displayed outstanding adaptability, effectively operating over a broad pH range from 5 to 9. Furthermore, the system demonstrated strong resistance to interference from sulfate (SO_4^(2-)) and nitrate (NO_3^-) ions. To elucidate the underlying reaction mechanisms, comprehensive analyses were conducted, including electron paramagnetic resonance (EPR) spectroscopy, radical quenching experiments, and probe compound tests. These investigations collectively confirmed that the highly efficient degradation of TC through the 25Co@Si-A/PMS system was attributed to a synergistic combination of radical and non-radical pathways. The primary reactive species involved were free radicals, dominated by sulfate radicals (SO_4^(2-)) with contributions from hydroxyl radicals (?OH), and non-radical singlet oxygen (1O2). The degradation mechanism was further enhanced by the nano-confined effect inherent to the aerogel's structure. This effect promoted several key processes: the concentration and enrichment of reactant molecules (both PMS and TC) within the pores, the increased exposure and accessibility of active catalytic sites, and the enhancement of electron transfer efficiency, which is crucial for the reaction. In conclusion, this research provides a novel and promising strategy for utilizing silica aerogel-based materials to activate PMS for the effective removal of tetracycline. The study offers substantial theoretical insights and crucial technical support for the future development and design of innovative cobalt-based catalytic materials supported on silica aerogels for advanced oxidation processes in water treatment applications.

Key words: peroxymonosulfate (PMS), silicon aerogel, Co@Si-A, nano-confined space, one-step sol-gel method, tetracycline

摘要： 本研究采用一步溶胶-凝胶法制备钴掺杂硅气凝胶催化剂(Co@Si-A)，并将其用于活化过一硫酸盐(PMS)降解水中四环素(TC)。结果表明，25Co@Si-A表现出最佳的催化活性，对TC的降解率达98.97%。BET分析显示，25Co@Si-A具有高比表面积和丰富的纳米限域空间结构；同时，25Co@Si-A/PMS体系展现出较宽的pH适用范围(5~9)和较强的抗SO_4^(2-)和NO_3^-干扰能力。电子顺磁共振(EPR)、猝灭试验及探针转化试验共同揭示，25Co@Si-A/PMS高效降解TC归因于体系中存在以SO_4^(?-)为主的自由基(SO_4^(?-)和?OH)及非自由基(1O2)的共同作用。该体系降解TC机理与纳米限域效应密切相关，此效应可有效促进反应物富集、增加活性位点暴露量以及提高电子转移效率。本研究为硅气凝胶材料活化PMS降解TC提供了新思路，并为开发基于硅气凝胶材料的新型钴基催化材料提供了重要的理论与技术支撑。

关键词: 过一硫酸盐(PMS), 硅气凝胶, Co@Si-A, 纳米限域空间, 一步溶胶-凝胶法, 四环素