摘要
以乙二胺(EDA)还原氧化石墨烯(GO)制得一种吸附材料,即还原态氧化石墨烯(RGO)。采用批量平衡法研究了RGO对Zn(Ⅱ)的吸附动力学与热力学,利用Lagergren准一级及准二级动力学方程、Langmuir和Freundlich等温方程对实验数据进行了拟合分析。研究结果表明,Lagergren准二级吸附动力学模型能够较好地描述实验结果,表明该吸附过程以化学吸附为主。RGO的吸附在所研究的Zn(Ⅱ)浓度范围内更符合Langmuir等温吸附经验式,ΔH0=-21.60 k J/mol,吸附焓变小于零,表明该吸附为放热过程;吸附吉布斯自由能变化ΔG0为正值,表明该吸附是一个非自发的过程。
Reduced graphene oxide （RGO） was prepared by reducing graphene oxide （GO） with ethylenediamine（EDA）. The adsorption kinetics and thermodynamics of Zn（Ⅱ） onto RGO were investigated with a batch method. The Lagergren pseudo-first-order and pseudo-second-order kinetic model, Langmuir and Freundlich isotherm models were applied to simulate the experimental data. The results show that the experimental data are well described with the Lagergren pseudo-second-order model, indicating that the adsorption process is chemisorption mainly. The adsorption isothermal process fits well with the Langmuir model. The enthalpy change is -21.60 kJ/mol and the Gibbs free energy is positive, which indicates that the adsorption of Zn（Ⅱ） is exothermic and non-spontaneous, respectively.
出处
《应用化学》
CAS
CSCD
北大核心
2014年第12期1458-1464,共7页
Chinese Journal of Applied Chemistry
基金
教育部科学研究重点项目(211124)
湖南省大学生研究性学习和创新性实验计划项目(湘教通[2012]141号)
湖南省自然科学基金(13JJ2030)资助项目~~
