有序介孔碳对罗丹明B的吸附行为研究

摘要

以嵌段共聚物F127为模板剂,间苯二酚/甲醛为碳源,在酸性条件下制备了孔径为6.44 nm,BET比表面积为661.98 m2/g,孔容为0.46cm3/g的有序介孔碳(Ordered Mesoporous Carbon,OMC).将所得有序介孔碳材料应用于罗丹明B(RhB)的吸附,并对吸附等温线和吸附动力学进行了研究.结果表明,吸附行为符合Langmuir吸附等温线及准2级动力学吸附.通过计算吸附过程中的吸附自由能△G0、焓△H0、熵△S0等热力学参数,表明吸附行为是自发进行的且是放热反应.溶液的pH值会对吸附量产生明显的影响,这主要是由于不同的pH值会对RhB的聚合产生明显的影响,从而导致分子尺寸的变化进而影响吸附量.%Ordered mesoporous carbon materials(OMC) was synthesized from polymerization of resorcinol and formaldehyde in the presence of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer(Pluronic F127) under acidic conditions. The obtained OMC with BET surface area of 661.98 m2/g, pore volume of 0.46 cm3/g and pore size of 6.44 run was applied for adsorption of Rhodamine B(RhB) dye from aqueous solution and the adsorption isotherm and adsroption kinetics were investigated. The results show that the adsorption process follows the Langmuir isotherm and pseudo-second-order kinetic models. The thermodynamic parameters free energy of adsorption (△G0), enthalpy (△H0) and entropy (AS0) changes were calculated and the obtained data indicates that the adsorption process is spontaneous and exothermic. The adsorption amount can be significantly influenced by the pH of the aqueous solution, because the pH can change the aggregation state of RhB and the size of RhB which will affect the adsorption amount of RhB onto OMC.