Graphitic Carbon Nitride Nanorods Modified TiO2 Nanotube Arrays with Enhanced Photocatalytic Activity for Phenol Degradation

TiO2 nanotubes (TiNTs)/graphite-like carbon nitride (g-C3N4) nanorod (NR) photocatalyst was synthesized by the droplet evaporation method followed by annealing. The aim of this research is to implement the environmental application of nanomaterial in terms of metal-free photocatalyst to treat organic pollutants. The as-prepared samples were characterized by X-ray powder diffraction, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and UV-vis diffuse reflectance spectrometry. The results reveal that g-C3N4 NRs were decorated on TiNTs. Moreover, the photocatalytic performance of TiNTs/g-C3N4 NR composite under simulated solar light was measured for phenol as a test pollutant. The results of phenol degradation showed that the photocatalytic activity of TiNTs/g-C3N4 NR composite was higher than that of as-synthesized TiNTs under simulated light. Furthermore, the photocatalytic efficiency of the TiNTs/g-C3N4 NR composite was improved due to decrease in the charge transfer resistance and efficient transfer of photogenerated electron/hole pairs. The rate of photocatalytic reaction was determined from the pseudo first-order kinetics. Photocatalytic mechanism was proposed to explain the electron/hole separation and transport over the TiNTs/g-C3N4 NRs as well as phenol degradation under simulated light irradiation.