Effects of fluorination modification on pore size controlled electrospun activated carbon fibers for high capacity methane storage.

Electrospun carbon fibers were prepared as a methane storage medium. Chemical activation was carried out using potassium carbonate to develop the pore structure, which can provide sites for the uptake of methane, and then fluorination surface modification was conducted to enhance the capacity of storage. Chemical activation provided a highly microporous structure, which is beneficial for methane storage, with a high specific surface area greater than 2500m(2)/g. The pore size distribution showed that the prepared samples have pore sizes in the range of 0.7-1.6nm. The effect of fluorination surface modification was also investigated. The functional groups, which were confirmed by XPS analysis, played an important role in guiding methane gas into the carbon silt pores via the attractive force felt by the electrons in the methane molecules due to the high electronegativity of fluorine. Eventually, the methane uptake increased up to 18.1wt.% by the synergetic effects of the highly developed micropore structure and the guiding of methane to carbon pores by fluorine.