(南华大学 城市建设学院污染控制与资源化技术湖南省重点实验室，衡阳 421001)
摘 要: 以氧化石墨烯(GO)、正硅酸乙酯(TEOS)为原料，聚氧乙烯-聚氧丙烯-聚氧乙烯(P123)为表面活性剂，利用TEOS水解成SiO2合成了氧化石墨烯/二氧化硅复合材料(GOS)。通过静态实验，探讨pH、GOS投加量、吸附时间和U(Ⅵ)初始浓度对GOS吸附U(Ⅵ)的影响，采用傅里叶变换红外光谱(FTIR)、X-射线衍射(XRD)、扫描电子显微镜(SEM)和能谱分析(EDS)对GOS进行表征，并探讨其吸附U(Ⅵ)的机理。结果表明:当溶液pH为6，投加量为0.2 g/L，吸附时间为120 min时，GOS吸附U(Ⅵ)效果最佳；吸附过程较好地拟合准二级动力学模型(R2≈1)和Freundlich等温模型(R2≈1)；SiO2成功与GO复合，GOS对U(Ⅵ)具有很好的吸附性能，其吸附U(Ⅵ)前后自身结构并未发生变化，其对U(Ⅵ)的吸附机理以—COOH、—OH的离子交换作用为主，Si—OH的络合反应并存。
关键字: 氧化石墨烯；二氧化硅；复合材料；铀(Ⅵ)；吸附
（Hunan Province Key Laboratory of Pollution Control and Resources Reuse Technology,
University of South China, Hengyang 421001, China）
Abstract:The graphene oxide/silica composite (GOS) was fabricated using graphene oxide (GO), ethylsilicate (TEOS) as the raw material, oxygen polyoxyethylene-polypropylene-polyoxyethylene (P123) as the surfactant. Through a static test, different experimental parameters, such as solution pH, dosing, initial concentration and contact time, were examined to investigate their effects on adsorption of uranium by GOS. The composite was investigated by FTIR, XRD, SEM and EDS. The results show that the optimal pH, addition, adsorption time are 6, 0.2 g/L and 120 min, respectively. The equilibrium data fit well with the pseudo-second-order model (R2≈1) and Freundlich model (R2≈1). Silicon dioxide has been successfully combined with GO. GOS has good adsorption effect on U(Ⅵ), and the GOS structure itself keeps unchanged during the adsorption. It is shown that both ion exchanges of —COOH and —OH play a major role, with the assistant of complexation reaction of Si—OH in the adsorption.
Key words: graphene oxide; silica; composite; uranium (Ⅵ); adsorption
