Abstract:

In order to preferably deal with the problem of azo dye pollution in the aquatic environment and make full use of China's abundant natural mineral resources, chrysotile mineral fibers were directly used as heterogeneous catalyst carriers in the experiment. While ensuring the economic application of mineral resources, it should make full use of various active components in chrysotile to explore a new path for the utilization of chrysotile mineral resources. NiCo₂O₄@chrysotile fiber (NC@CF) with core-shell structure was prepared by hydrothermal-calcination method, which was used to activate peroxydisulfate (PDS) to degrade methyl orange (MO). The mechanism of MO degradation in NC@CF/PDS system was investigated by scanning electron microscopy, Fourier transform infrared spectroscopy and other material characterization methods. The results showed that the combination of NiCo₂O₄ and chrysotile had a synergistic effect in the degradation process of MO. The removal rate of MO by NC@CF-2/PDS system with a load ratio of 2∶1 could reach 94.50% under the optimal conditions, and the degradation process conformed to the pseudo-first-order kinetic model. In addition, combined with free radical quenching experiments, electron paramagnetic resonance, X-ray photoelectron spectroscopy and electrochemical experiments, it was shown that the degradation of MO in the NC@CF-2/PDS system was completed by the synergistic effect of the free radical pathway of ·OH and SO₄^-· and the non-free radical pathway of electron transfer.

Key words: potassium persulfate, inhomogeneous oxidation, chrysotile, nickel cobalt oxide (NiCo₂O₄), methyl orange

摘要：

为了更好地处理水环境中的偶氮染料污染问题，充分利用我国储量丰富的天然矿物资源，实验中直接使用纤蛇纹石矿物纤维作为非均相催化剂载体处理难降解废水问题。在保证矿物资源应用经济性的同时，充分利用纤蛇纹石中的多种活性组分，以探索纤蛇纹石矿产资源利用新路径。本文通过水热-煅烧法制备具有核壳结构的复合材料NiCo₂O₄@纤蛇纹石纤维（NC@CF），将其用于活化过二硫酸盐（PDS）降解甲基橙（MO），并结合扫描电子显微镜、傅里叶变换红外光谱等材料表征手段对NC@CF/PDS体系降解MO的机理展开探究。结果表明：NiCo₂O₄和纤蛇纹石的结合在MO的降解过程中具有协同作用，负载比为2∶1的NC@CF-2/PDS体系在最优条件下降解MO，去除率可达94.50%，降解过程符合准一级动力学模型。此外，结合自由基淬灭实验、电子顺磁共振、X射线光电子能谱分析以及电化学实验表明，NC@CF-2/PDS体系中MO的降解是在·OH和SO{}_{\mathrm{4}}^{-}·的自由基途径和电子转移的非自由基途径的协同作用下完成的。

关键词: 过硫酸钾, 非均相催化, 纤蛇纹石, 钴酸镍, 甲基橙