Synthesis and Characterization of WO₃/CeO₂ Heterostructured Nanoparticles for Photodegradation of Indigo Carmine Dye

Abstract

WO₃/CeO₂ heterostructured nanocomposites containing different WO₃ ratios (0.1, 0.3, 0.5, and 1.0 wt %) were synthesized by a precipitation method. The coupling of CeO₂ and WO₃ with a high specific surface area noticeably enhanced the photocatalytic activity of indigo carmine (IC) degradation under visible-light irradiation. The degradation rate constants (<i>k</i>) of 0.5 wt % WO₃/CeO₂ nanocomposites reached 4 and 5 times higher than those of CeO₂ and WO₃, respectively. Regarding the experimental results, the X-ray diffraction (XRD) patterns of the CeO₂ spherical nanoparticles and rod-shaped WO₃ were assigned to the cubic fluorite and orthorhombic phase structures, respectively. The increasing photocatalytic activity of nanocomposite samples could be attributed to the heterojunction of the photocatalysts with efficient charge separation and strong oxidative ability, which were confirmed by the photoluminescence spectra and diffuse reflectance spectrometry. The staggered heterojunction of the nanocomposite promoted efficient electron transfer and suppressed the recombination of photogenerated electrons and holes during the process.