The impacts of graphene concentration and thickness on the photocatalytic performance of Bi₁₂TiO₂₀/graphene composite thin films

Bi 12 TiO 20 /graphene thin films with different graphene concentration and thickness were deposited through spin coating followed by post annealing. The thin film morphology was determined by SEM images, which showed a granular structure. Both elemental mapping and EDX spectrum confirmed that the Bi 12 TiO 20 and graphene phases were homogenously distributed within the thin film. The crystal structure of Bi 12 TiO 20 was determined by XRD, and the existence of graphene was determined by Raman spectrum. The Rama spectrum also showed that the graphene had similar states in all Bi 12 TiO 20 /graphene thin films with different graphene concentration. The photocatalytic testing showed that the mass ratio graphene to Bi 12 TiO 20 at 4% showed the highest photocatalytic performance, and when the thin film was over 100 nm, the thickness did not affect the photocatalytic performance.