Superior dispersion of highly reduced graphene oxide in N,N-dimethylformamide

► The hydrazine reduction of GO in DMF/water at different temperatures was investigated. ► The relationships between the highly reduced graphene oxide (HRG) properties were established. ► The HRGs exhibited a high electrical conductivity and good dispersibility in DMF. ► The reduction of GO in DMF-rich media at low temperature is the key factor.