Recovery of poly sulfide anions in basic solution produced by the decomposition of H₂S by fullerene

To remove poly sulfide anions from basic solution, a fullerene/toluene solution was mixed with an aqueous solution containing S₂ ^2- ions and agitated until the color of the aqueous phase changed from yellow to transparent. The treatment was repeated several times. During each treatment, white precipitates were produced in the aqueous phase and black crystals were formed after 4th treatment. XRD results indicated that former was elemental sulfur and the latter, fullerene-sulfur compounds. Thus, we succeed in extracting and separating poly sulfide ion from aqueous solution. By the fifth treatment, c.a. 675 S₂^2- ions per one fullerene were successfully collected from the aqueous solution. This reaction can be applied to recovery of other anion species in basic solution.