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以聚合多巴胺为碳源制备碳材料包覆的磁性纳米颗粒.通过多巴胺的自聚合反应将其包覆在Fe_3O_4纳米颗粒上,在氩气保护下高温灼烧得Fe_3O_4@C复合材料.包覆碳材料后,Fe_3O_4颗粒的稳定性和分散性提高.使用扫描电镜、透射电镜、红外光谱和振动磁强计对材料进行了表征.结果表明成功地制备了核壳结构的Fe_3O_4@C复合材料.用甲基绿来考察Fe_3O_4@C的吸附性能.研究表明,溶液pH对甲基绿的吸附有显著的影响,随溶液pH的升高,甲基绿的吸附容量显著增大.用朗格缪尔吸附等温模型拟合出在纯水、湖水和自来水中Fe_3O_4@C对甲基绿的最大吸附容量分别为490.1、442.5和389.1 mg·g~(-1).热力学研究计算出吸附的吉布斯自由能为负值,说明吸附是自发过程.动力学研究表明甲基绿在Fe_3O_4@C上的吸附过程符合拟二级反应动力学方程,吸附速率较快.
Polymeric dopamine was used as carbon source to prepare magnetic nanoparticles coated with carbon material, which was coated on Fe_3O_4 nanoparticles by self-polymerization reaction of dopamine and was calcined at high temperature under the protection of argon to obtain Fe_3O_4 @ C composites. The stability and dispersity of Fe 3 O 4 particles were improved by SEM, TEM, FTIR and Vibration magnetometer.The results showed that the Fe 3 O 4 @ C composite with core-shell structure was prepared successfully. Methyl green to investigate the adsorption properties of Fe 3 O 4 @ C. The results show that the pH of the solution has a significant effect on the adsorption of methyl green, with the increase of solution pH, methyl green adsorption capacity significantly increased with Langmuir The maximum adsorption capacity of Fe 3 O 4 @ C to methyl green in pure water, lake water and tap water was 490.1, 442.5 and 389.1 mg · g -1, respectively, according to the adsorption isotherm model. Thermodynamic study calculated the adsorption capacity of Gibbs The free energy is negative, indicating that adsorption is a spontaneous process.Kinetic studies show that the adsorption of methyl green on Fe 3 O 4 @ C conforms to the pseudo-second-order reaction kinetics equation, and the adsorption rate is faster.