I reduced graphene oxide by NaBH4 and Hydrizine but both rGOs couldn't be re-dispersed in Toluene? In different articles for functionalization of rGO by some organic molecule, rGO first dispersed in Toluene.
Dispersion of graphene can be done using various methods, probe sonication will work best for situation like yours wherein you are using an organic solvent. However we have been successful in reducing graphene using plant extract and have got a good dispersion. you may read our article "Nanoscale Research Letters (2015) 10:281"