低温碳纳米管的XPS光谱特征研究

XPS Study on Surface of Low-temperature Prepared Carbon Nanotubes by Post-treatment

采用X射线光电子能谱对后处理前后的低温碳管(LT-CNTs)进行表面特征分析.发现纯化后碳管的O/C原子比升高,经过Ar气保护下的高温煅烧的后处理后,其O/C原子比降低,比表面积增大.对C1 s峰的拟合分析表明,碳管表面的含氧基团发生改变,深度纯化碳管时,大量活性碳原子变为羟基(C-O),大量的羰基(C=O)变为羧基(O-C=O).同时,大部分化学吸附的氧气将解吸,氧气的解吸将使C-O键或O-C=O转变为C=O双键等形式,且伴随碳管电学性质的改变,由明显的金属性转变为半导体性.

X-ray photoelectron spectroscopy （XPS） was used to investigate the surface characteristics of the lowtemperature prepared carbon nanotubes after pest-treatment. The results indicated that the O/C ratio was increased through purification and decreased by annealing in the protection of Ar gas. Through C1s curve-fitting of low-temperature carbon nanotubes, it was found that the oxygenous groups of surface carbon nanotubes was changed by purification and annealing. The part of oxygen atoms was desorbed from the surface of CNTs through the formation of CO and CO2 ,the adsorption of oxygen causes the transformation of C - O bond to C = O double bond with the characteristics of electricity being also changed.