常压下Fe3O4@C磁性复合材料的制备及其对亚甲基蓝的吸附

以共沉淀法合成的Fe₃O₄为载体，在常温常压下，利用浓硫酸蔗糖碳化法制备出Fe₃O₄@C磁性复合材料，通过傅里叶变换红外光谱仪（FTIR）、X射线粉末衍射仪（XRD）、扫描电镜（SEM）、透射电镜（TEM）和磁学测量系统（MPMS）手段对合成的磁性复合材料进行表征，并研究了Fe₃O₄@C对水中亚甲基蓝的吸附性能。考察了吸附剂用量、溶液pH、吸附温度、震荡时间等因素对吸附过程的影响。结果表明，Fe₃O₄@C表面分布有大量不规则的孔道，其饱和磁化强度为18.45emu/g；当亚甲基蓝初始浓度为100mg/L，吸附剂加入量1g/L，吸附时间150min，吸附温度25℃，pH=12时，得到吸附容量为96.74mg/g。Fe₃O₄@C对水中亚甲基蓝的吸附符合Langmuir模型，吸附过程动力学符合准二级动力学方程，吸附过程是吸热及熵增加的过程；Fe₃O₄@C经过稀硫酸溶液解吸之后可以重复利用。

Preparation of magnetic Fe3O4@C composites under ambient pressure and their adsorption of methylene blue

Under ambient temperature and pressure, the magnetic Fe₃O₄@C was synthesized by sulfuric acid sucrose carbonization method and with Fe₃O₄ synthesized by co-precipitation and as the carrier. The resulting products were characterized by Fourier transform infrared spectra(FTIR), X-ray powder diffraction(XRD), scanning electron microscope(SEM), transmission electron microscope (TEM), and magnetic property measurement system(MPMS). The Fe₃O₄@C was tested for the ability to remove methylene blue(MB). The effects of adsorbent dosage, solution pH, adsorption temperature and oscillating time on the adsorption process were investigated. The results showed that there are a lot of irregular holes in the surface of Fe₃O₄@C and its saturation magnetization is 18.45emu/g. When the initial concentration of MB is 100mg/L, adsorbent dosage is 1g/L, adsorption time is 150min, adsorption temperature at 25℃, pH=12, the maximum adsorption capacity reaches 96.74mg/g. The experimental data fitted well with Langmuir model. The adsorption kinetic fitted well with the pseudo-second-order kinetic, and the adsorption of MB was an endothermic and the confusion degree increase process. Fe₃O₄@C could be regenerated by washing with H₂SO₄ aqueous solution.