Properties of zirconia/polyaniline hybrid nanocomposites and their applicability for photocatalytic degradation of model pollutants

Abstract A serie of novel ZrO 2 /Polyaniline (PANI) hybrid nanocomposite powders were successfully synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate (APS) in water, in the presence of ZrO 2 nanoparticles. Syntheses were performed at initial ZrO 2 /aniline mole ratios 50, 100 and 150 to produce ZP-50, ZP-100 and ZP-150. The morphological, structural, and optical properties of the synthesized nanocomposites were studied using Transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Raman, UV-Vis and Electron-paramagnetic resonance (EPR) spectroscopies. EPR spectra of ZP-50 and ZP-100 nanocomposites showed the presence of intensive peak at the g-values comparable to that for free electrons (2.0023) indicating the presence of oligo/poly (semiquinone radical cations), i.e. polarons as charge carriers in PANI part; ZP-150 showed weak polaron peak of PANI, and peak that can be assigned to defects in zirconia matrix (Zr 3+ , oxygen vacancies). The monoclinic crystal structure of ZrO 2 nanoparticles in all nanocomposites was confirmed by XRD and by Raman spectroscopy. The photocatalytic activities of ZP nanocomposites were evaluated using the photocatalytic degradation of trichlorophenol (TCP) and Rhodamine B model compounds and compared with the activity of bare ZrO 2 nanoparticles. Enhanced degradation efficiencies of nanocomposites regarding TCP degradation were observed.