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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,合成了GO/SiO_2复合材料。通过静态吸附试验,探讨了pH、GO/SiO_2投加量、吸附时间和Cd(Ⅱ)初始浓度对GO/SiO_2吸附Cd(Ⅱ)的影响,采用了FTIR、XRD、SEM和EDS对GO/SiO_2吸附Cd(Ⅱ)进行表征分析,并探讨了其对Cd(Ⅱ)的吸附机制。结果表明,当溶液pH为8.5,投加量为0.25g/L,吸附时间为100min时,GO/SiO_2吸附Cd(Ⅱ)效果最佳。吸附过程较好的拟合了准二级动力学模型(R~2≈1)和Freundlich等温吸附模型(R~2≈1)。XRD表明SiO_2与GO成功复合;FTIR、SEM等结果表明,GO/SiO_2吸附Cd(Ⅱ)前后自身结构并未发生变化,其对Cd(Ⅱ)具有很好的吸附效果,对Cd(Ⅱ)的吸附机制以—OH、—COOH的离子交换作用为主,Si—OH的络合反应并存。
GO / SiO_2 composites were synthesized by using GO and TEOS as raw materials and P123 as surfactant. The effects of pH, GO / SiO 2 dosage, adsorption time and Cd (Ⅱ) initial concentration on the adsorption of Cd (Ⅱ) onto GO / SiO_2 were investigated by static adsorption experiments. Adsorption of Cd (Ⅱ) for characterization and analysis of its Cd (Ⅱ) adsorption mechanism. The results showed that the adsorption of Cd (Ⅱ) on GO / SiO_2 was the best when the pH was 8.5, the dosage was 0.25g / L and the adsorption time was 100min. The adsorption process better fit the pseudo-second order kinetic model (R ~ 2≈1) and the Freundlich isotherm model (R ~ 2≈1). The results of XRD, FTIR and SEM showed that the structure of Cd (Ⅱ) did not change before and after the adsorption of Cd (Ⅱ) onto GO / SiO_2, which showed good adsorption effect on Cd (Ⅱ) Adsorption mechanism to-OH, -COOH ion exchange-based, Si-OH complexation co-exist.