丙烯酸接枝改性氧化石墨烯及其对Ce(Ⅲ)的吸附性能研究

Grafting modification of graphene oxide with acrylic acid and its adsorption properties for Ce(Ⅲ)

以氧化石墨烯为基材,通过接枝丙烯酸单体,对其进行功能化改性,制备出对Ce(Ⅲ)具有良好吸附性能的吸附材料(GO-g-PAA)。系统研究了吸附时间、溶液pH值等不同实验条件对Ce(Ⅲ)吸附行为的影响。结果表明,GO-g-PAA用于吸附Ce(Ⅲ)时可在100 min达到吸附平衡,吸附过程符合准二级吸附动力学方程和Langmuir等温吸附模型,属于化学吸附和单分子层吸附,其理论最大吸附量为251.9 mg/g。XPS谱图证实GO-g-PAA吸附Ce(Ⅲ)时属于阳离子交换机理。此外,GO-g-PAA在pH=1时对Ce(Ⅲ)的吸附量仍可达到101.9 mg/g,说明该吸附剂可在强酸性条件下使用,因此GO-g-PAA在去除废水中的稀土离子污染物方面具有良好的应用前景。

The adsorption material(GO-g-PAA)with good adsorption properties for Ce(Ⅲ)was prepared by grafting acrylic monomer onto graphene oxide.The effects of different experimental conditions such as adsorption time and pH value on the adsorption capacity of Ce(Ⅲ)were systematically studied.The results showed that the adsorption equilibrium of Ce(Ⅲ)onto GO-g-PAA could be achieved within 100 min.The adsorption behavior was well fitted to the pseudo-second-order kinetic model and the Langmuir adsorption model,which implies that the adsorption is a chemisorption process and single molecular adsorption.The theoretical maximum adsorption capacity of GO-g-PAA for Ce(Ⅲ)uptake was 259.1 mg/g.The XPS analysis confirmed that the adsorption of Ce(Ⅲ)by GO-g-PAA belongs to cation exchange mechanism.In addition,The GO-g-PAA adsorbent exhibited high adsorption capacity of Ce(Ⅲ)(101.9 mg/g)at pH of 1,suggesting that GO-g-PAA could be used in some extreme conditions due to its high acidic resistance.Therefore,GO-g-PAA has a good application prospect in the removal of rare earth ions pollutants from wastewater.