Abstract: PAN-ACF(polyacrylonitrile activated carbon fiber) was firstly impregnated with Ni(NO₃)₂·6H₂Oby using 2-propanol as the solvent. By this method, nickel ion can be dispersed effectively in/on the micropore's entrance or external surface, which were made as an active site for coking to modify the micropore size in a narrower range. The porous structures of PAN ACFwere studied by means of nitrogen adsorption. The micropore size and micropore volume were calculated by Horvath Kawazoe(H-K) equations. The results showed that the ultramicropore concentrated on about 048 nm and the micropore volumes were 019-025 mL/g. The whole pore size distribution was obtained by using density functional theory(DFT). It was shown that the micropore was mainly concentrated on 0.6-0.8 nm. After being washed by acid and deionized water, the sample's BETsurface area and micropore volume were improved and the average pore size kept unchanged, this may be due to the catalyst loaded in the ultramicropore resolved by acid leaving more adsorption space. An X-ray diffractometer(XD-3XA) was used to observed the spectra of samples. It was shown that nickel ion might be effectively dispersed in ACF, the existence of NiOparticles were ascribed to the oxidation by air, and which were dissolved through acid treatment. A-JEM-EX1200 electron microscopy was used to examine the morphologies of PAN ACFs. The SEMresults showed that the sample impregnated with nickel ion could be well distributed by deposited carbon than that without nickel ion. All the results demonstrated that the microstructures of PAN-ACFcould be modified by CVDusing nickel ion as the catalyst for coking.

Key words: PAN ACF, Microstructure, Nickel nitrate, Catalytic vapour deposit(CVD)