Methyl orange degradation by pulsed discharge in the presence of activated carbon fibers

The effects of activated carbon fibers (ACF0, ACFH, and ACFN) on the degradation of methyl orange were investigated in a pulsed discharge reactor. ACF0 fibers were modified with nitric acid (to yield ACFH fibers) or ammonia (to yield ACFN fibers) to create fibers with different porous structures and chemical properties. The adsorption properties of ACF0, ACFH, and ACFN depended on their pore diameter, but the catalytic properties were independent of their chemical properties. Acidic and basic surfaces both accelerated ozone decomposition, resulting in formation of hydroxyl radicals. Boehm titration and Fourier-transform infrared spectral studies indicated that the numbers of acidic and basic groups on ACF0, ACFH, and ACFN surfaces could be increased by this process, as could the surface areas and pores volumes. ACF0, ACFH, and ACFN could also be regenerated in situ after repeated use.