Effect of nitrogen doping on the photocatalytic activity and hydrophobic property of rutile TiO2 nanorods array

Abstract

Pure titanium dioxide (TiO2) and nitrogen (N)–doped TiO2 nanorods array were prepared using polished Ti substrates and hydrothermal synthesis method. Prepared nanorods films were characterized by different techniques including X‐ray diffractometer (XRD), field‐emission scanning electron microscope, Fourier‐transform infrared spectroscopy, and XPS. The photocatalytic activities of both prepared films were evaluated by their capacity to degrade methylene blue (MB) in solution, and an attempt to associate it with their surface wetting properties is achieved. The XRD results showed that the prepared TiO2 is of rutile phase. Furthermore, the 3%N‐doped TiO2 nanorods films show similar high crystallinity and photocatalytic activity compared with prepared films of TiO2 rutile phase. Additionally, their surface wetting properties were studied and showed hydrophobic behavior with contact angle higher than 120°. The hydrophobicity of 3%N‐doped TiO2 nanorod films is shown to be enhanced because of TiO2 nanorods diameter decreasing. Additionally, the results clearly show that the prepared 3%N‐doped TiO2 nanorods films exhibit both higher hydrophobicity and the best photocatalytic activity toward the degradation of MB under visible light irradiation.