ADSORPTION BEHAVIOR OF FORMALDEHYDE ON PAN-ACFs

Adsorption of formaldehyde on PAN ACFs modified by solution impregnation was investigated. Nitrogen adsorption isotherms were determined. It was found that the BET surface area and micropore volume of modified ACF decreased, while the adsorption capacity of formaldehyde increased. In addition, the sample ACF1 with low specific surface area had lower formaldehyde adsorption capacity than that of ACF2 with relatively high specific surface area. The adsorbed formaldehyde couldn't be removed at the temperature lower than 150?℃. It was conferred that the adsorption behavior was controlled by both surface functional groups and pore structure of ACF. The elemental analysis showed that the content of C and N in modified samples increased, while the content of O decreased, which illustrated that nitrogen functional groups played an important role in formaldehyde adsorption. After post heat treatment, adsorption capacity of formaldehyde on samples ACF1 and ACF2 both increased, which showed that heat treatment can increase active sites on ACFs by removing heteroatoms.