Three-dimensional graphene networks modified photocatalyst with high performance under visible-light irradiation

- 3DGNs prepared by CVD approach was used to hybridize with TiO2.
- Large BET area of 3DGNs improves adsorption ability of the resulting catalyst.
- Lower recombination rate of photo-induced electron-hole pairs is achieved.
- Sensitization of 3DGNs endows visible-light activity for the resulting catalyst.

Graphene is considered as a promising modifier to improve the photocatalytic performances of TiO2 due to its excellent electrical property. However, due to the high defect density and low BET area of the widely adopted reduced graphene oxide (RGO), practical performances of the reported RGO-TiO2 composite photocatalysts are not as good as expected. In this study, three-dimensional graphene networks (3DGNs) prepared by chemical vapor deposition approach is adopted to fabricate composite photocatalyst with TiO2 (3DGNs-TiO2). Results manifest that corresponding decomposition rate constant of phenol increases more than 100% and 30% compared to that case of adopting pure TiO2 and the RGO-TiO2 under UV-light illumination, respectively. Continuous three-dimensional structure of the 3DGNs provides fast transport channel for electrons (and depresses the recombination of photo-induced electron-hole pairs in the photocatalyst). Moreover, the resulting 3DGNs-TiO2 displays good catalytic activity under visible-light irradiation due to the sensitization of the 3DGNs.