Visible-Light Induced Photodegradation of Organic Contaminants in Water Using Fe3O4 Nanoparticles Modified Polypyrrole/Fly Ash Cenosphere Composite

Abstract

Ternary nano-composites of polypyrrole/iron oxide/fly ash cenosphere (PPY/Fe₃O₄/FAC) were synthesized and used as magnetic photocatalyst. The synergistic effect of FAC, a buoyant carrier and polypyrrole, a conducting polymer enhanced the photocatalytic activity. Different composites were synthesized by varying the concentration of Fe₃O₄ and FAC to evaluate its effect on the photocatalytic properties of composites. The presence of Fe in Fe²⁺ and Fe³⁺ oxidation states at binding energies of 709.3 and 711.4 eV respectively was depicted by XPS curve. PPY/Fe₃O₄/FAC (1 : 3) composite showed the highest photocatalytic activity with rate constant (k) 0.0058 min^–1. The removal efficiency of BPA was found to be around 75% and ~62% total organic content (TOC) was eliminated at optimized conditions from the solution. Transmission electron microscopy (TEM) showed the cluster morphology of the PPY/Fe₃O₄/FAC nano-composites with ~6–10 nm size of Fe₃O₄. X-ray diffraction studies elucidated the characteristic peaks of both PPY and Fe₃O₄ at 2θ ~ 20°–30°, and 26.04°, respectively in the composites which also confirmed the interaction of PPY with Fe₃O₄.