Fabrication, characterization and application of a reusable immobilized TiO2-PANI photocatalyst plate for the removal of reactive red 4 dye

method for immobilizing TiO2-PANI composite using ENR and PVC as adhesives was successfully developed. The immobilized system known as TiO2/PANI/ENR/PVC plate was characterized by FTIR, Raman, diffuse reflectance UV-vis, photo luminescence spectroscopy and HRTEM. The optimum weight ratio for the TiO2:PANI composite was 1:0.0035. The band gap energy of the optimum immobilized composite TiO2/PANI/ENR/PVC (1: 0035) was 2.86 eV where polyaniline (PANI) formed a core-shell coating of about 0.9 nm with a strong TiO2-PANI interaction. Photo-etching of the immobilized TiO2/PANI/ENR/PVC( 1: 0.0035) composite for 7 h increased its surface area and improved its photocatalytic activity. TiO2/PANI/ENR/PVC (1: 0.0035)-7 h was visible light sensitive where 85% of 30 mg L-1 reactive red 4 (RR4) dye was decolorized after 60 min of irradiation. The immobilized TiO2/PANI/ENR/PVC (1: 0.0035)-7 h was reusable and its photocatalytic activity was sustainable with an average pseudo first order rate constant value of 0.103 +/- 0.002 min(-1). Adding PANI to the immobilized P25 TiO2 has enhanced its photocatalytic activity throughout the entire ten recycled applications due to the increased BET surface area and lower e(cb) and h(+) recombination. (C) 2014 Elsevier B. V. All rights reserved.