期刊
APPLIED SURFACE SCIENCE
卷 254, 期 1, 页码 247-250出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.apsusc.2007.07.120
关键词
multi-walled carbon nanotubes (MWCNT); surface functionalization; X-ray photoelectron spectroscopy (XPS); temperature-programmed desorption (TPD)
Multi-walled carbon nanotubes were exposed either to nitric acid or to an oxygen plasma to synthesize oxygen-containing functional groups which were characterized by high-resolution X-ray photoelectron spectroscopy (XPS). The C ls spectra revealed that the treatment with nitric acid mainly resulted in the formation of carboxylic (COOR) and phenolic (C-OR) groups, whereas the plasma treatment led to a higher amount of carbonyl (C=O) groups. Furthermore, the nitric acid treatment yielded a 60% higher surface oxygen concentration compared to the plasma treatment, and created a minor amount of nitrogen-containing functional groups. Thus, the nitric acid treatment was found to be more effective in creating acidic functional groups. The presence and the thermal stability of these groups was also investigated by temperature-programmed desorption (TPD). The release of carbon dioxide was detected at about 350 and 450 degrees C, indicating the decomposition of COOR groups. The C=O groups were more stable decomposing even above 600 degrees C. In addition, ammonia was adsorbed as probe molecule followed by TPD to derive the amount and the acidity of the carboxylic and phenolic groups. (C) 2007 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据