Fui Hui, Ma Xinran, Huang Yiping, Xi Shiyao, Ren Zhandong, Zhu Yuchan
Hubei Province Key Laboratory of Agricultural Waste Resource Utilization, Wuhan Polytechnic University Wuhan 430023 China
School of Chemistry and Environmental Engineering, Wuhan Polytechnic University Wuhan 430023 China.
RSC Adv. 2025 Aug 28;15(37):30817-30828. doi: 10.1039/d5ra04080a. eCollection 2025 Aug 22.
AS a low-cost and high-performance catalyst, spinel cobalt oxide (CoO) has two different catalytic active sites (tetrahedral Co and octahedral Co) to drive the activation of peroxymonosulfate (PMS) through Co/Co redox cycle. Tuning Co/Co atomic ratio on the surface of CoO for the construction of a synergy in the Co/Co redox cycle might be an effective way to further boost PMS activation performance of CoO catalyst. Herein, we suggested a metal-doping strategy to regulate Co/Co atomic ratio of CoO by partially substituting Co with inert Mg and formed a series of Mg doped CoO (MCO) catalysts. Structural characterizations and experimental investigations demonstrated that Mg doping did not change CoO host lattice and particle morphology, but could manipulate surface Co/Co atomic ratio of CoO for an improved PMS activation. The optimal MCO catalysts (MCO-0.2) with the suitable Co/Co atomic ratios (1.13) exhibited the excellent thiacloprid (THIA) degradation performance through PMS activation, and the apparent degradation rate constant (0.2835 min) was highly outperformed that of pure CoO (0.09555 min) and other similar cobalt-based catalysts. The optimal THIA degradation conditions might be: catalyst dose 100 mg L, PMS concentration 0.8 mM, pH 7 and THIA concentration 20 mg L. Quenching experiments and electron paramagnetic resonance (EPR) characterizations suggested SO˙, HO˙ and O were all involved in THIA degradation during the MCO-0.2/PMS process. Furthermore, the steady-state concentrations of these reactive species and their relative contributions to THIA degradation were also calculated by combining a kinetic model and a series of probe compound-based experiments. The results indicated that SO˙ and HO˙ were generated at lower steady-state concentrations than that of O, but they dominated THIA abatement during the MCO-0.2/PMS process. This study presented new insights into the construction of efficient PMS activator and a mechanistic understanding for PMS-mediated reaction.
作为一种低成本、高性能的催化剂，尖晶石型氧化钴（CoO）具有两个不同的催化活性位点（四面体Co和八面体Co），可通过Co/Co氧化还原循环驱动过一硫酸盐（PMS）的活化。调节CoO表面的Co/Co原子比以构建Co/Co氧化还原循环中的协同作用，可能是进一步提高CoO催化剂PMS活化性能的有效方法。在此，我们提出了一种金属掺杂策略，通过用惰性Mg部分替代Co来调节CoO的Co/Co原子比，并形成了一系列Mg掺杂的CoO（MCO）催化剂。结构表征和实验研究表明，Mg掺杂不会改变CoO主体晶格和颗粒形态，但可以控制CoO的表面Co/Co原子比以改善PMS活化。具有合适Co/Co原子比（1.13）的最佳MCO催化剂（MCO-0.2）通过PMS活化表现出优异的噻虫啉（THIA）降解性能，表观降解速率常数（0.2835 min）远高于纯CoO（0.09555 min）和其他类似的钴基催化剂。最佳的THIA降解条件可能为：催化剂剂量100 mg/L，PMS浓度0.8 mM，pH 7，THIA浓度20 mg/L。猝灭实验和电子顺磁共振（EPR）表征表明，在MCO-0.2/PMS过程中，SO˙、HO˙和O均参与了THIA的降解。此外，还通过结合动力学模型和一系列基于探针化合物的实验，计算了这些活性物种的稳态浓度及其对THIA降解的相对贡献。结果表明，SO˙和HO˙的稳态浓度低于O，但在MCO-0.2/PMS过程中它们主导了THIA的去除。本研究为高效PMS活化剂的构建提供了新的见解，并对PMS介导的反应有了机理上的理解。
