Synthesis and characterization of structural, optical, thermal and dielectric properties of polyaniline/CoFe_2O_4 nanocomposites with special reference to photocatalytic activity

摘要

In this study we have synthesized polyaniline/CoFe_2O_4 nanocomposites (PANI@CFs) by in situ polymerization method with different amounts of the CoFe_2O_4 nanoparticles NPs (CF-NPs) (0.5 g and 1.0 g). The structural optical, thermal and dielectric properties of the as synthesized PANI@CFs were studied. The XRD analysis ensures that CF-NPs have a single phase spinel structure. The XRD and EDAX results confirmed that the CF-NPs were successfully incorporated in the PANI matrix. The crystalline size analysis revealed that the size increased with increasing CF-NPs amount in the PANI@CFs, because of the aggregation effect. TGA exhibited an enhanced thermal stability of the PANI@CFs as compare with PANI owing to the strong interaction between the CF-NPs and polymer matrix. The energy band gaps as calculated through the Tauc relation were found to be gradually higher with the increasing the amount of CF-NPs in PANI@CFs. The dielectric constants (ε′, ε″), dielectric loss (tan δ) and AC conductivity (σ_(ac)) were studied as the function of frequency and composition, which have been explained by 'Maxwell Wagner Model'. The high dielectric constant and ac conductivity were observed of PANI@CFs than PANI. Moreover, PANI@CF 1:2 exhibited the promising photocatalytic activity for the photo-decoloration of the methyl orange (MO) dye under UV light irradiation. Results also showed protection of photo-decoloration of the MO dye by the disodium ethylenediaminetetraacetate dehydrate (EDTA-Na_2; C _(10)H_(14)N_2Na_2O_8× 2H_2O) (hole scavenger) and tert-butyl alcohol (C_4H _(10)O) (radical scavenger) clearly suggested the implication of reactive oxygen species (ROS) in the photocatalytic activity of PANI@CF 1:2. It is encouraging to conclude that PANI@CF bears the potential of its applications in photocatalysis.