Surface decoration of WO3 architectures with Fe2O3 nanoparticles for visible-light-driven photocatalysis

Abstract

Zero-dimensional Fe₂O₃ nanoparticles were successfully decorated on three-dimensional WO₃ architectures to constitute a photocatalyst of Fe₂O₃@WO₃ heterojunction. The obtained samples were characterized in detail by X-ray diffraction, scanning electron microscopy, elemental mapping, X-ray photoelectron spectroscopy and UV-Vis absorption spectra. The results indicate that rhombohedral α-Fe₂O₃ nanoparticles are homogeneously decorated on the surface of monoclinic WO₃ architectures, and the constituted n⁺–n heterojunction results in “redshift” of the optical absorption. The photocatalyst of 1%Fe₂O₃@WO₃ annealed at 400 °C exhibits the highest photocatalytic activity for degradation of Rhodamine B under visible light irradiation. The degradation obeys first-order reaction kinetics with an apparent rate constant of 0.057 min⁻¹. It is suggested that the potential-energy difference between Fe₂O₃ and WO₃ accelerates the separation of photogenerated electron–hole pairs, dominating the enhanced photocatalytic activity. The results presented herein provide new insight for development of a novel visible-light-driven photocatalyst and its potential application in harmful pollutant degradation.