Preparation of the new polyaniline/ZnO nanocomposite and its photocatalytic activity for degradation of methylene blue and malachite green dyes under UV and natural sun lights irradiations

A new polyaniline (PANI) homopolymer and PANI/ZnO nanocomposite have been successfully synthesized in aqueous diethylene glycol solution medium via the chemical oxidative polymerization of aniline. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, FTIR spectra, UV–vis spectroscopy measurements were used to characterize the resulting PANI homopolymer and PANI/ZnO nanocomposite photocatalysts. The photocatalytic activities of PANI homopolymer and PANI/ZnO nanocomposites were investigated by the degradation of methylene blue (MB) and malachite green (MG) dyes in aqueous medium under natural sunlight and UV light irradiation and the efficiency of the catalysts have been discussed in detail. Results indicate that the addition of the ZnO nanoparticles to the PANI homopolymer enhance the photocatalytic efficiency under natural sunlight irradiation and a little amount of PANI/ZnO nanocomposite photocatalyst (0.4 g/L) degrades both of the dye solutions (MB or MG) with 99% efficiency after 5 h of irradiation under natural sunlight.

Photodegradation of dyes under natural sunlightFigure optionsDownload as PowerPoint slideHighlights
► The polyaniline matrix was synthesized first time in aqueous diethylene glycol solution medium.
► The ZnO nanoparticles were synthesized in de-ionized water by arc-discharge method.
► The photocatalytical activity of the PANI/ZnO nanocomposite under UV and natural sunlight irradiations were studied.
► The photocatalyst amount was used as lower with respect to literature but higher photodegradation rates have been obtained.