(南華大學 城市建設學院污染控制與資源化技術湖南省重點實驗室，衡陽 421001)
摘 要: 以氧化石墨烯(GO)、正硅酸乙酯(TEOS)為原料，聚氧乙烯-聚氧丙烯-聚氧乙烯(P123)為表面活性劑，利用TEOS水解成SiO2合成了氧化石墨烯/二氧化硅復合材料(GOS)。通過靜態(tài)實驗，探討pH、GOS投加量、吸附時間和U(Ⅵ)初始濃度對GOS吸附U(Ⅵ)的影響，采用傅里葉變換紅外光譜(FTIR)、X-射線衍射(XRD)、掃描電子顯微鏡(SEM)和能譜分析(EDS)對GOS進行表征，并探討其吸附U(Ⅵ)的機理。結果表明:當溶液pH為6，投加量為0.2 g/L，吸附時間為120 min時，GOS吸附U(Ⅵ)效果最佳；吸附過程較好地擬合準二級動力學模型(R2≈1)和Freundlich等溫模型(R2≈1)；SiO2成功與GO復合，GOS對U(Ⅵ)具有很好的吸附性能，其吸附U(Ⅵ)前后自身結構并未發(fā)生變化，其對U(Ⅵ)的吸附機理以—COOH、—OH的離子交換作用為主，Si—OH的絡合反應并存。
關鍵字: 氧化石墨烯；二氧化硅；復合材料；鈾(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
