Camphorsulfonic acid-doped polyaniline/TiO2 nanotube hybrids: synthesis strategy and enhanced visible photocatalytic activity

Camphorsulfonic acid doped polyaniline (CSA-PANI) was prepared by a doping-dedoping-redoping process, and subsequently used for modifying the TiO2 nanotube arrays (TNTs) on titanium surfaces via a facile impregnation method. The obtained CSA-PANI/TNTs hybrids were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV-Vis diffuse reflectance spectroscopy and photocurrent tests. The photocatalytic activities of the hybrids were measured by the degradation of Rhodamine B (RhB) under visible-light irradiation (lambda > 420 nm). The results indicate the hybridization between CSA-PANI and TiO2 greatly enhances the photocatalytic activity of TNTs. The CSA-PANI (100 mg/L) hybridized TNTs photocatalyst displays the highest photocatalytic activity for RhB decomposition. Conductive CSA-PANI polymer can arouse visible light absorption and accelerate the separation of photo-induced electron-hole pairs. A possible mechanism on the CSA-PANI/TNTs photocatalytic activities is suggested. Such a photocatalyst should be promising for photocatalytic degradation of organic pollutants using solar energy.