Synthesis and characterization of structural, optical, thermal and dielectric properties of polyaniline/CoFe₂O₄ nanocomposites with special reference to photocatalytic activity

• Javed Alam Khan^a, 
• Mohd Qasim^b, 
• Braj Raj Singh^a, , , 
• Sneha Singh^a, 
• Mohd Shoeb^a, 
• Wasi Khan^a,
• Dibakar Das^b, 
• Alim H. Naqvi^a

• Abstract

  In this study we have synthesized polyaniline/CoFe₂O₄ nanocomposites (PANI@CFs) by in situpolymerization method with different amounts of the CoFe₂O₄ 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-Na₂; C₁₀H₁₄N₂Na₂O₈⋅2H₂O) (hole scavenger) and tert-butyl alcohol (C₄H₁₀O) (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.