Efficiently separating carriers is the major challenge for degrading stable volatile-aromatic compounds by photocatalysis. Here, we propose using TaON to modify V2O5 to construct heterojunction for improving the charge separation efficiency. The 5 wt% TaON/V2O5 exhibited the optimal photocatalytic activity in degradation of toluene, reaching to 40% mineralization ratio after 30 h irradiation, which was 2.1 and 1.5 times higher than TaON and V2O5, respectively. The enhanced photocatalytic activity was mainly ascribed to the improved separation efficiency of carriers by the interface electric field of heterojunction. The mass spectrum and electron paramagnetic resonance analyses distinctly demonstrated that the toluene was first oxidized by OH to generate cyclohexane-1,2,3,4,5,6-hexaol. Then, it reacted with 'OH, " O2 and h+ to change into xylose and methoxyacetaldehyde until they were mineralized to CO2.