Doping nitrogen anion enhanced photocatalytic activity on TiO2 hybridized with graphene composite under solar light

► A simple strategy for preparing nitrogen-doped graphene/TiO2 composite was reported. ► The photocatalytic activity of graphene/TiO2 was remarkably enhanced in present of nitrogen anion. ► The enhancement can be related to improvement of light absorption and electron transfer. ► The approach is possible applied for preparation of other graphene based photocatalyst.