利用硝酸铈铵对活性炭纤维进行了化学改性。研究了铈盐改性前后活性炭纤维的微观结构和表面化学结构的变化。结果表明,活性炭纤维经铈盐处理后,比表面积降低10%~20%左右,微孔孔径分布没有发生明显的变化,表面氧含量从原子分数11%提高至25%,使活性炭纤维表面形成更多的高价态含氧基团。并通过X射线光电子能谱和热重-红外联用的分析结果相结合,较为详细地、定量地分析了活性炭纤维表面的含氧基团。结果表明,利用热重一红外联用技术对活性炭纤维表面含氧基团的种类及其相对量分析结果与基于X射线光电子能谱的C1s分峰结果定量分析基本一致,两种结果可互为验证。
The surface chemical structure of activated carbon fibers (ACF) was modified by cerous nitrate. The pore structure and surface chemical structure were characterized by nitrogen adsorption, X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis-Fourier transformation infrared integrated technology. Resuits show that Ce(IV)-treatment can result in about a 10-20 % decrease of specific surface area of the modified ACF, however this treatment cannot obviously change the micro-pore size distribution. Surface chemical structure analysis based on XPS indicates that Ce (Ⅳ)-treatment can evidently increase the oxygen content of ACF from 11 to 25 atom% depending on the concentration of cerous nitrate. In situ IR analysis of the decomposition gases from ACF during heating to high temperature shows that the chemical treatment of ACF with a higher concentration of cerous nitrate can form many oxygen-containing groups such as carboxyl or lactone groups on the modified ACF, which is consistent with the results based on XPS.