Visible light-induced photocatalytic and antibacterial activity of TiO 2 /polyaniline-kapok fiber nanocomposite

Anatase TiO2 nanoparticles with an average crystallite size of around 6.06 nm were successfully immobilized on the surface of polyaniline-coated kapok fiber (PANI-KpF) via hydrothermal reaction. The photocatalytic activity of the TiO2/PANI-KpF nanocomposite was studied under visible light using methyl orange (MO) and Cr(VI) as model pollutants. Photodegradation of MO was achieved using nanocomposites prepared with 0.5 and 1.0 mL titanium isopropoxide (TTIP) with removal efficiencies of about 87.4 and 76.8%, respectively. These are about 13 and 18% higher than the removal efficiencies under dark conditions. On the other hand, visible light-induced photo-reduction of Cr(VI) was carried out in the presence of isopropanol (IPA) as a hole scavenger, with 100% removal efficiency. Without IPA, Cr(VI) was removed by adsorption. The TiO2/PANI-KpF also showed antibacterial activity against E. coli bacteria under visible light.