GO/AT复合材料的制备及其吸附性能分析

采用溶液共混法制备氧化石墨烯(GO)/凹凸棒石(AT)复合材料,探讨GO含量对复合材料吸附性能的影响,并对复合材料的组成和微观结构进行了表征和分析。结果表明,当GO/AT的质量比为3/4时,复合材料对盐酸四环素的吸附效果最佳,吸附率达到93.06%。进一步探讨了吸附时间、盐酸四环素初始浓度和溶液pH条件对复合材料吸附性能的变化,分析了复合材料吸附盐酸四环素的过程;GO/AT复合材料对盐酸四环素的吸附过程符合准二级动力学方程,其表观吸附活化能为37.19 kJ/mol,此吸附过程以静电吸附为主;对盐酸四环素的吸附行为符合Langmuir等温式,在研究的温度范围,吸附焓变(ΔHO)为7.77 kJ/mol,吸附自由能变(ΔGO)<0,吸附熵变(ΔSO)为57.62 J/(mol·K),表明该吸附是吸热、自发、熵增过程。

Preparation and Adsorption Performance of Graphene Oxide/Attapulgite Composites

Graphene oxide(GO)/attapulgite(AT)composites were prepared by a solution blending method.The effect of the mass ratio of GO/AT on the adsorption capacity of the composites was investigated,and the phase composition and microstructure of the composites were analyzed.The results indicated that the composites gained a maximum adsorption capacity when the mass ratio of GO/AT was 3/4,and their adsorption rate reached 93.06%.The effects of adsorption time,the initial concentration of tetracycline hydrochloride,and the pH values on the removal of tetracycline hydrochloride from aqueous solution were further investigated,and the mechanism and process of tetracycline hydrochloride adsorption were explored.The adsorption behavior of the composites for tetracycline hydrochloride was found to comply with the Langmuir isothermal equation and quasi second-order kinetic model with apparent adsorption activation energy of 37.19 kJ/mol.This indicated that the adsorption behavior was dominated by electrostatic adsorption.Moreover,the adsorption process was determined as an endothermic,spontaneous and entropy increasing process in the temperature range of this study according to the important parameters ofΔHO=7.77 kJ/mol,ΔGO<0 andΔSO=57.62 J/(mol·K).