Synthesis of polyaniline/titanium dioxide nanocomposite (PAni/TiO2) and its application as photocatalyst in acrylic pseudo paint for benzene removal under UV/VIS lights

Nowadays, there is a special attention on air purification by photocatalytic oxidation (PCO) of pollutants. In this study, polyaniline/titanium dioxide nanocomposite (PAni/TiO2) was synthesized by in situ oxidative polymerization. The polymerization was carried out in dodecyl benzene sulfonic acid (DBSA) micellar solution that acted as both dopant and surfactant. The resultant PAni/TiO2 nanocomposite was characterized by different analysis (i.e. FTIR, SEM, XRD, DRS and TGA). Results showed that the band gap of the PAni/TiO2 nanocomposite decreased compared to the nano TiO2, whilst its optical responsivity under visible light increased. Thereafter, photo oxidative acrylic pseudo-paints were prepared by using TiO2 nanoparticles and PAni/TiO2 nanocomposite. They were used to degrade gaseous benzene in air under UV and VIS lights. Photocatalytic performance of the pseudo paints were evaluated by GC analysis. It was found that using PAni/TiO2 nanocomposite instead of nano TiO2 in pseudo paints caused 50% decrement in the benzene removal (i.e. PCO activity) under UV light. However, the benzene removal increased 23% under VIS light. In addition, the effects of adding TiO2 pigment and CaCO3 into the pseudo paints were investigated. It was found that using these micro particles caused decrement in the benzene removal of the nano TiO2 containing sample but had no effect on the sample that contained PAni/TiO2 nanocomposite. It was also found that pseudo paints containing neat polyaniline could also remove benzene under both UV and VIS lights. However, it was much lower than the performance of the pseudo paints containig PAni/TiO2 nanocomposite.