A novel reduced graphene oxide-supported hollow Co₃O₄@N-doped porous carbon (Co₃O₄@NPC/rGO) composite was synthesized via self-assembly and pyrolysis-oxidation using bimetallic zeolite imidazolate frameworks and graphene oxide as precursors. The as-obtained composite exhibited superior performance on peroxymonosulfate (PMS) activation over a wide pH range. Complete removal of sulfamethoxazole (SMX, 25 mg·L⁻¹) was achieved within 5 min and the reaction rate constant was higher than those of the most reported heterogeneous catalyst/PMS systems for SMX degradation. It was demonstrated that both radical pathways (SO₄⁻, OH, and O₂⁻) and non-radical pathways (¹O₂ and direct electron transfer) were involved in the SMX degradation. Significantly, the contribution ratio of each reactive oxidative species (ROS) in the bulk solution or on the catalyst surface was differentiated and calculated for the first time. SO₄⁻ both in the bulk solution and on the catalyst surface as well as the ¹O₂ in the bulk solution were the dominant ROS. The possible degradation mechanism of SMX by Co₃O₄@NPC/rGO/PMS system was proposed. Co active sites with high activity, the electron-rich ketonic group and the nitrogen doping sites within Co₃O₄@NPC/rGO contributed to the excellent catalytic activity. The ecotoxicity of SMX and its intermediates was investigated. Besides, the reusability, stability and application potential in actual waterbodies of Co₃O₄@NPC/rGO were evaluated. Overall, this work expands the environmental application of metal–organic frameworks (MOFs)-derived hollow nanomaterials and provides a promising heterogeneous catalyst for the elimination of refractory contaminants by sulfate radical-based advanced oxidation processes (SR-AOPs).

使用双金属沸石咪唑酯骨架和氧化石墨烯作为前体，通过自组装和热解氧化合成了一种新型的还原氧化石墨烯负载的空心 Co ₃ O ₄ @N 掺杂多孔碳（Co ₃ O ₄ @NPC/rGO）复合材料。所获得的复合材料在较宽的 pH 范围内表现出优异的过硫酸盐 (PMS) 活化性能。磺胺甲恶唑 (SMX, 25 mg·L ^-1 ) 在 5 分钟内完全去除，反应速率常数高于大多数报道的用于 SMX 降解的非均相催化剂/PMS 系统。结果表明，两种自由基途径（SO ₄ ^-、OH 和 O₂ ^- ) 和非自由基途径（¹ O ₂和直接电子转移）参与了 SMX 的降解。重要的是，首次区分并计算了本体溶液中或催化剂表面上每种活性氧化物质（ROS）的贡献率。本体溶液中和催化剂表面上的SO ₄ ^-以及本体溶液中的¹ O ₂是主要的 ROS。提出了 Co ₃ O ₄ @NPC/rGO/PMS 系统降解 SMX 的可能机制。高活性Co活性位点、富电子酮基和Co ₃ O内的氮掺杂位点₄ @NPC/rGO 促成了优异的催化活性。研究了 SMX 及其中间体的生态毒性。此外，还评估了 Co ₃ O ₄ @NPC/rGO在实际水体中的可重用性、稳定性和应用潜力。总体而言，这项工作扩展了金属有机骨架（MOFs）衍生的中空纳米材料的环境应用，并为通过基于硫酸根自由基的高级氧化工艺（SR-AOPs）消除难熔污染物提供了一种有前景的多相催化剂。