水溶性富勒烯对U(VI)在氧化多壁碳纳米管上吸附的影响

Effect of Hydroxylated and Carboxylated Fullerenes on Oxidized  Multi-walled Carbon Nanotubes Adsorbing U(VI)

中文关键词:  羟基化富勒烯  羧基化富勒烯  U(VI)  吸附  氧化多壁碳纳米管

英文关键词:oMWCNTs  U(VI)  Adsorption  C₆₀(OH)n  C₆₀(C(COOH)₂)n

中文摘要:

      采用静态试验法研究了水溶性富勒烯对U(VI)在氧化多壁碳纳米管上吸附的影响。结果表明,羟基化富勒烯(C₆₀(OH)n)和羧基化富勒烯(C₆₀(C(COOH)₂)n)的加入对U(VI)在氧化多壁碳纳米管上的吸附量影响作用类似。在pH<3范围内,羟基化富勒烯和羧基化富勒烯对吸附几乎没有影响,在pH>3以后,二者开始抑制碳纳米管对U(VI)的吸附。较低浓度(10 mg/L)的C₆₀(OH)n对U(VI)的吸附几乎没有影响。而等量的C₆₀(C(COOH)₂)n已呈现出明显的抑制作用。但两者的作用机理不同,前者可能是由于羟基化富勒烯和U(VI)竞争氧化多壁碳纳米管上的吸附位点造成的,后者则可能改变了氧化多壁碳纳米管的表面电荷。用双位点模型对不同固液比和U(VI)初始浓度下U(VI)的吸附率随C₆₀(OH)n和C₆₀(C(COOH)₂)n初始浓度的变化进行了拟合得到了很好的结果。

英文摘要:

      The adsorption of U(VI)on oxidized multi-walled carbon nanotubes(oMWCNTs)as a function of two kinds of soluble fullerene(i.e.hydroxylated fullerene(C₆₀(OH)n)and carboxylated fullerene(C₆₀(C(COOH)₂)n) were studied under ambient conditions using batch techniques. The results indicated that the drastic effect of C₆₀(OH)n and C₆₀(C(COOH)₂)n on the adsorption of U(VI) on oMWCNTs have almost not been found at pH<3, whereas the negative effect was observed at pH>3. No obvious inhibition effect on U(VI) adsorption was induced by C₆₀(OH)n at a lower concentration. C₆₀(C(COOH)₂)n showed a significant effect at 10 mg/L. The mechanism of C₆₀(OH)n may be contributed to the competitive adsorption sites on oMWCNTs between C₆₀(OH)n and U(VI).The surface charge of oMWCNTs may be changed by C₆₀(C(COOH)₂)n.The double site sorption model (DSSM) was applied to simulate the adsorption isotherms of U(VI) in the presence of C₆₀(OH)n and fitted the experimental data well.