Characterization and surface modification of carbon nanowalls

The microstructure and surface features of carbon nanowall (CNW) thin films has been investigated by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). It is found that CNWs have a surface chemical state comprising a mixture of sp(2) and a few sp(3) bonds. Some oxygen atoms are chemically absorbed on the CNW surface. The valence band XPS spectra revel the CNW shows a band structure like normal crystalline graphite materials. Hydrogen plasma treatment technique is employed to modify the CNW surface, which is evidenced to be an efficient approach to increase CNW surface areas, benefiting to host and anchor catalyst substances.