核壳结构Fe3O4@C粒子在UV-Fenton氧化去除VOCs过程中的吸附-催化作用

采用一步水热法制备核壳结构Fe₃O₄@C微米粒子,通过比表面积及孔径分析仪、X射线衍射仪、透射电子显微镜、傅里叶变换红外光谱仪等对粒子结构和形貌进行表征,并研究了粒子作为非均相催化剂在UV-Fenton氧化去除挥发性有机物(VOCs)中的作用机制.结果表明,核壳结构Fe₃O₄@C粒子由于包覆了孔隙状碳层而具有较强的吸附能力,可显著增加VOCs气体分子与Fenton试剂的接触几率,有助于提高VOCs的去除效率.通过计算反应速率常数及协同因子,证实在核壳结构Fe₃O₄@C粒子去除VOCs的过程中存在吸附-催化氧化协同作用. 

Fabrication of Fe3O4@C core-shell particles and its application in UV-Fenton oxidize removal of VOCs

The solvothermal method was used to prepare Fe₃O₄@C core-shell microspheres. The structure and morphology of the nanocomposite powders were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy, and then the particles were used as heterogeneous catalysts in the UV-Fenton removal of VOCs in gas. The results show that the Fe₃O₄@C core-shell microspheres have a strong adsorption capacity for VOCs due to the outer layer of Fe₃O₄ being coated with a carbon layer of uniform thickness and pore structure. For sparingly soluble organic gases such as octane, the adsorption of these particles could increase the total concentration of VOCs in the liquid phase. Therefore, the opportunity for the Fenton reagent to be in contact with the VOCs gas increases, causing a significant improvement in the gas removal efficiency. Moreover, the cooperation factor β was introduced to evaluate the synergistic effects in the integrated process of the adsorption-catalytic oxidation by the core-shell structure particles.