Enhanced photocatalytic activity exhibited by PTh/[Fe(CN)3(NO)(bpy)]·4H2O nanocomposite fibers via a synergistic approach

Abstract

Successful synthesis of a photoadduct, [Fe(CN)₃(NO)(bpy)]·4H₂O and its use as a filler in polythiophene (PTh) matrix for synthesizing PTh/[Fe(CN)₃(NO)(bpy)]·4H₂O nanocomposite fibers by chemical polymerization. [Fe(CN)₃(NO)(bpy)]·4H₂O exhibited wide transparency in the entire visible region, thereby showing non-linear optical behavior (NLO) which has been confirmed by a second harmonic generation (SHG) test. The fibrous structure of the nanocomposite has been confirmed from TEM. Thermal analysis revealed increased thermal stability of the nanocomposite fibers than pure PTh. A dielectric study showed the capacitive effect of the nanocomposite fibers at low frequencies and a conductivity effect at high frequencies. This behavior may provide an absorptive and reflective mechanism to EMI shielding. Meanwhile, a higher photocatalytic activity of the present material for methyl orange (MO) dye has been observed than for many other two component systems as reported in the literature. This has been attributed to the presence of a synergistic effect between PTh and photoadduct particles which is believed to play an essential role in affecting the photoreactivity. From BET, the surface area of the nanocomposite has been found to be 18.9 m² g⁻¹. The main contributing factor to the enhanced photocatalytic activity of the nanocomposite fibers has been attributed to the interface contact between PTh and photoadduct particles, as is evidenced by PL measurements. Also, the degradation mechanism of the photocatalytic process has been proposed and the active species involved to cause degradation are confirmed by using different scavengers. Kinetic study revealed the degradation process to follow second order kinetics with an observed rate constant of 7 × 10⁻⁴ L mol⁻¹ s⁻¹.