  Carbon nanotubes (CNTs) have attracted increasing attention because of their
unique structural, mechanical, and electronic properties. Surface chemistry
modifications are also useful and critical to manipulate the adsorptive
properties of CNTs and develop their potential of environmental application.
Therefore, the main objectives of this study were to investigate the optimal
synthesis methods or characteristics identification of multiwall CNTs (MWCNTs)
and the environmental application of lead ions adsorptive removal by CNTs.
Experimentally, the MWCNTs of well-graphited walls were obtained with reductive
potassium metals of catalytic hexachlorobenzene-thermal routes in the presence
of Co/Ni catalyst precursors at 503-623 K for 8- 12 hr. The diameters of MWCNTs
ranged of 30-100 nm by TEM microphotos. In addition, fine structures or surface
chemical modification of MWCNTs or Co/Ni precursors were further identified by
EDS, XRPD, X-ray absorption near edge structural (XANES) or extended Xray
absorption fine structural (EXAFS) spectroscopy. 1.
