In order to further improve its photocatalytic activity, the BiOI microspheres were activated by a synchronous coupling of Bi metal and graphene under solvothermal conditions. The effects of the synthesis temperature (160-200 degrees C) on crystallinity, morphology, and photocatalytic activity were studied in particular. As expected, the ternary Bi-BiOI/graphene photocatalyst synthesized at 180 degrees C exhibited higher photocatalytic activity for NO oxidation removal under visible light irradiation than individual BiOI, and binary Bi-BiOI and BiOI/graphene composites. The photocatalytic efficiency for the NO removal of the ternary Bi-BiOI/graphene photocatalyst synthesized at 180 degrees C reached 51.8% within 30 min of visible light irradiation. The enhanced photocatalytic activity of the ternary Bi-BiOI/graphene photocatalyst is attributed to (I) the efficient transfer of photo-generated electrons from BiOI and Bi to graphene, leading to the effective separation of the photo-generated electron-hole pairs and (II) the surface plasmon resonance effect of Bi nanoparticles in the composite photocatalyst. Furthermore, the results of the scavenger experiments and DMPO-ESR spin-trapping measurements reveal that center dot O(2)(-)radical species play the most critical role and holes serve as a secondary active species in the oxidative removal process of NO by 180BOI/GR composite under visible light irradiation.