Hybrid reduced graphene oxide/TiO2/graphitic carbon nitride composites with improved photocatalytic activity for organic pollutant degradation

The triple-component composites (rGO/TiO2/CN) were fabricated from the mixtures of the reduced graphene oxide (rGO) nanosheets, anatase TiO2 nanoparticles (NPs), and graphitic carbon nitride (g-C3N4) via simple mechanical stirring followed by calcination process. The rGO/TiO2/CN-0.75 sample with the optimal weight ratio exhibits improved photocatalytic activity, evidenced by methylene blue degradation, which is attributed to the synergistic effect of the incorporation of rGO and g-C3N4 with TiO2. The porous-layered structure of rGO and g-C3N4 encourages excellent dispersion of TiO2 NPs and consequently increases absorption sites and photocatalytic reaction sites. Meanwhile, the g-C3N4 expands visible-light absorption range and enhances the light harvest. Furthermore, rGO accelerates the photogenerated carrier separation and effectively suppresses charge recombination in the composites due to the excellent conductivity. The results provide a facile and promising strategy for enhancing the photocatalytic performance of TiO2-based composite photocatalysts.