Coupling of graphene oxide into titania for purification of gaseous toluene under different operational conditions

• Graphene oxide (GO)–TiO2 composites were prepared using a chemical mixing process.
• Photocatalytic activity of GO–TiO2 composites was much higher than that of P25 TiO2.
• Flow rate and initial concentration were major factors for photocatalytic activity.
• GO–TiO2 composite could be effectively activated by visible-light irradiation.
• GO–TiO2 composite could be applied effectively for purification of gaseous toluene.

Graphene oxide (GO)–titania (TiO2) composite was synthesized using a chemical mixing process and its photocatalytic activity for the degradation of a toxic organic vapor (toluene) under different operational conditions was examined. The as-prepared GO–TiO2 and undoped TiO2 photocatalysts were characterized using SEM, XRD, and UV–VIS–NIR spectra. Moreover, the photocatalytic degradation efficiency of the GO–TiO2 composite was much higher than that of the P25 TiO2, with an average efficiency of the GO–TiO2 composite of 84% and an average efficiency of the TiO2 powder of just 13%. As the air flow rate increased from 1 to 4 L min−1, the average degradation efficiencies of toluene decreased from 86 to 32%. In addition, as the initial concentration increased from 0.1 to 1.0 ppm, the average degradation efficiencies of toluene decreased from 86 to 8%. Overall, the GO–TiO2 composite could be applied effectively for purification of gaseous toluene under optimal operational conditions.