Synthesis And Performance Of Activated Carbon Composites For Magnetic Separation

Activated carbon(AC) possesses the unique microporous structure, high specific surface area and pore volume, AC has the strong adsorption performance for the pollutants in the air and water, such as small particles, macromolecular, heavy metal ion and so on. Moreover, owing to the complicated microporous structure and specific surface area, AC can be treated as an excellent template, various of functional materials(such as magnetic materials, photocatalyst, adsorbing materials, et al) can be coated on the surface of AC or implanted into the pore of AC to synthesize the AC composites with excellent properties. Because of the high specific surface area and good magnetic properties, magnetic AC composites are effective adsorptive materials for the removal of organic dyes and can be separated with a simple method.In this thesis, different magnetic mediums loaded AC composites are synthesized by several chemical methods and the adsorptive performance are studied by methylene blue MB adsorption of as-prepared AC composites. Then the magnetic response and adsorptive performance are optimized through adjusting the molar ratio of magnetic medium to AC.1、A series of CoxFey/Co Fe2O4/AC composites are synthesized by the sol-gel method, all the samples possess good magnetic response and strong adsorptive capacity of MB. The influence of AC content on the phase, magnetic properties and adsorption performance of composites are studied. With the increasing AC, CoxFey/Co Fe2O4/AC composites show the weaker magnetic response and decreasing adsorptive capacity of MB. Moreover, owing to the adequate Ms(13.33 emu/g) and highest specific surface area(962.78 m2·g-1), the as-prepared sample with the molar ratio of Co:Fe:AC=1:2:150(CFA/AC-150) are most suitably for the dealing with wastewater and can be retrieved with magnetic separated technique fast and simply.2、A series of Co Fe2O4/AC composites are synthesized by the hydrothermal method, all the samples possess good magnetic response and strong adsorptive capacity of MB. The influence of AC content on the phase, magnetic properties and adsorption performance of composites are studied. With the increasing AC, CoxFey/Co Fe2O4/AC nanocomposites show the weaker magnetic response and decreasing adsorptive capacity of MB. Owing to the adequate Ms(5.11 emu/g) and highest specific surface area(1096.85 m2·g-1), the as-prepared sample with the molar ratio of Co:Fe:AC=1:2:200(CF/AC-200) composites are most suitably for the dealing with wastewater and can be retrieved with magnetic separated technique fast and simply and can be retrieved with magnetic separated technique fast and simply.3、A series of Co Fe2O4/AC composites are synthesized by the micro-emulsion method, all the samples possess good magnetic response and strong adsorptive capacity of MB. The influence of Ni content and AC on the phase, magnetic properties and adsorption performance of composites are studied. With the increasing AC, Ni/AC composites show the weaker magnetic response and decreasing adsorptive capacity of MB. Owing to the adequate Ms(3.39 emu/g) and highest specific surface area(1156.85 m2·g-1), the as-prepared sample with the molar ratio of Ni : AC=1:50(Ni/AC-50) composites are most suitably for the dealing with wastewater and can be retrieved with magnetic separated technique fast and simply.Besides, the study show that the pore structure of AC can be destroyed at a certain extent, which causes the reducing of specific surface area and pore volume of magnetic AC, so as the adsorptive capacity. The hydrothermal method and micro-emulsion method have no effect on the pore structure of AC. The Ni/AC-50 and CF/AC-200 exhibit the similar adsorptive behavior of MB and adequate Ms, but Ni/AC-50 has the worse stability for the oxidation of Ni and complex process for the micro-emulsion method. Therefore, CF/AC-200 composite prepared by hydrothermal method is considered to possess the best properties in this thesis.Finally, based on the optimized CF/AC-200 sample, Ti O2/Co Fe2O4/AC composites are synthesized by the sol-gel method. And results turn out that all the samples not only possess good magnetic response but also have strong adsorptive capacity of MB. Under the UV light, Ti O2/Co Fe2O4/AC composites possess the good photocatalytic performance. With theincreasing Ti O2, as-prepared Ti O2/Co Fe2O4/AC composites possess the high crystallinity of Ti O2 and increasing photocatalytic performance.