Visible light-induced photocatalytic degradation of Reactive Blue-19 over highly efficient polyaniline-TiO2 nanocomposite: a comparative study with solar and UV photocatalysis

• Published in: Environmental science and pollution research international 2018-02, Vol.25 (4), p.3731-3744
• Main Authors: Kalikeri, Shankramma, Kamath, Nidhi, Gadgil, Dhanashri Jayant, Shetty Kodialbail, Vidya
• Format: Article
• Language: English
• Subjects: Anatase; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Catalytic activity; Chemical oxygen demand; Comparative studies; comparative study; crystallites; Degradation; Dyes; Earth and Environmental Science; Ecotoxicology; energy; Energy gap; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fibers; Fibrous structure; hydrodynamics; Industrial wastes; Industrial wastewater; Industrial wastewater treatment; Light; Mineralization; Nanocomposites; Nanoparticles; pH effects; Photocatalysis; photocatalysts; Photodegradation; Polyanilines; polymerization; Reaction kinetics; Research Article; solar radiation; Tips; Titanium dioxide; Ultraviolet radiation; Waste Water Technology; Wastewater treatment; Water Management; Water Pollution Control; X-ray diffraction
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-017-0663-1

Polyaniline-TiO 2 (PANI-TiO 2 ) nanocomposite was prepared by in situ polymerisation method. X-ray diffractogram (XRD) showed the formation of PANI-TiO 2 nanocomposite with the average crystallite size of 46 nm containing anatase TiO 2 . The PANI-TiO 2 nanocomposite consisted of short-chained fibrous structure of PANI with spherical TiO 2 nanoparticles dispersed at the tips and edge of the fibres. The average hydrodynamic diameter of the nanocomposite was 99.5 nm. The band gap energy was 2.1 eV which showed its ability to absorb light in the visible range. The nanocomposite exhibited better visible light-mediated photocatalytic activity than TiO 2 (Degussa P25) in terms of degradation of Reactive Blue (RB-19) dye. The photocatalysis was favoured under initial acidic pH, and complete degradation of 50 mg/L dye could be achieved at optimum catalyst loading of 1 g/L. The kinetics of degradation followed the Langmuir-Hinshelhood model. PANI-TiO 2 nanocomposite showed almost similar photocatalytic activity under UV and visible light as well as in the solar light which comprises of radiation in both UV and visible light range. Chemical oxygen demand removal of 86% could also be achieved under visible light, confirming that simultaneous mineralization of the dye occurred during photocatalysis. PANI-TiO 2 nanocomposites are promising photocatalysts for the treatment of industrial wastewater containing RB-19 dye.