Highly efficient visible light driven photocatalytic activity of MnO2 and Polythiophene/MnO2 nanohybrids against mixed organic pollutants

The present study reports green synthesis of MnO2 nanoparticles and its nanohybrids with polythiophene (PTh). MnO2 was synthesized using the extract of Syzygium Aromaticum (Dry clove) while PTh/MnO2 nanohybrids were formulated using different loadings of the conducting polymer. The synthesized materials were characterized using FTIR, UV-Vis, XRD, SEM, EDS along with elemental mapping and TGA to explore their structural, optical, morphological and thermal properties. The indirect band gap of MnO2 was calculated to be 2.47 eV and 1.84 eV for PTh. The nanohybrids revealed band gap values ranging between 1.5 eV-2.0 eV. The photocatalytic degradation of toxic organic pollutants such as Malachite Green (MG) dye, mixture of MG dye and trichlorophenol (TCP) were investigated. The PTh/MnO2 nanohybrids showed superior photocatalytic performance as compared to pure PTh and MnO2. Maximum photocatalytic degradation of MG dye under visible light was found to be 92%, 83%, 95% and 97% within 80 min using MnO2 , PTh, 25% - PTh/MnO2, 15% - PTh/MnO2 photocatalysts respectively. For the mixture of MG-TCP, the maximum degradation was found to be 98% for MG dye and 97% for TCP using 15%-PTh/MnO2 while, in case of 25%- PTh/MnO2, the values were calculated to be 91% for MG dye and 93% for TCP. (C) 2020 Elsevier B.V. All rights reserved.