Heterogeneous activation of peroxymonosulfate over monodispersed Co 3 O 4 /activated carbon for efficient degradation of gaseous toluene

•Activated carbon supported monodispersed Co3O4 nanoparticles (Co3O4/AC) were prepared via a facile deposition method.•The presence of Co-OH+ on Co3O4/AC is highly efficient in PMS activation for gaseous toluene degradation.•SO4− play a dominant role for toluene degradation, HO derived from PMS activation can improve carbon mineralization.•Few gaseous intermediates were discharged during reaction process.