Zlata Hrnjak-Murgic
University of Zagreb, Croatia
Title: Solar-driven photocatalytic wastewater treatment using PEDOT/TiO2 nanocomposite catalyst: Comparison of various catalysts structure
Biography
Biography: Zlata Hrnjak-Murgic
Abstract
TiO2 is an excellent photocatalyst under UV light but its high band gap limits its activity under visible light and restricts the practical application. The PEDOT conductive polymer was used to increase the photocatalytic activity of TiO2 as conductive polymers are known to be efficient electron donor and good electron transporters upon visible-light excitation. For that reason the nanocomposite photocatalysts of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and TiO2 nanoparticles were prepared by in-situ synthesis for catalytic waste water treatment. The synthesis was carried out by chemical oxidation polymerization with FeCl3 oxidant with the ratio EDOT monomer:oxidant 1:1, while the ratio of monomer and TiO2 nanoparticles was 1:10 and 1:20. Studied photocatalysts were characterized by FTIR spectroscopy, SEM microscopy, TG analysis and by the determination of conductivity. The photocatalytic activity was assessed through degradation of Acid Blue 25 dye (AB25) under simulated Solar irradiation. Photocatalysis was monitored by measuring discoloration of AB25 using UV/Vis spectroscopy. The kinetics of photocatalytic degradation of AB25 was determined as well. The effect of photocatalytic media on catalysts efficiency was also considered due to strong interactions between catalyst and pollutant.
The results indicate the strong interactions of PEDOT polymer and AB25 because very high adsorption of dye onto PEDOT/TiO2 nanocomposite catalysts was observed. The pH media of suspension during catalytic water treatment significantly affected those interactions and photocatalysis process.