Promoted charge separation and specific surface area via interlacing of N-doped titanium dioxide nanotubes on carbon nitride nanosheets for photocatalytic degradation of Rhodamine B

Titanium dioxide (TiO2) has been regarded as a promising catalyst owing to its superior charge transport properties in photocatalytic degradation of organic pollutants and photocatalytic hydrogen generation. However, a major bottleneck toward the utilization of TiO2 photocatalysts is inefficient exploitation of visible light and low adsorption behavior. To address this issue, we fabricated a hybrid nanocomposite composed of one-dimensional N-doped TiO2 nanotubes (N-TNTs) and two-dimensional graphitic carbon nitride nanosheets (g-CNNs) to improve photocatalytic behavior. Furthermore, photogenerated electron-hole pairs in the hybrid N-TNT/g-CNN composites were efficiently separated by introducing g-CNNs. In addition, the improved specific surface area provided many active sites, resulting in higher photocatalytic reactions in kinetics. Based on these features, the Rhodamine B photocatalytic degradation efficiency was the highest, similar to 85%, under solar-light irradiation in the N-TNT/g-CNN composites (7 wt% of the g-CNN content), which is two times higher than that of the N-TNT. Moreover, excellent durability and stability were observed after four cycles, which can be attributed to the extended optical absorption range and enhanced separation of the photogenerated electron-hole pairs.