Visible light degradation of ibuprofen using PANI coated WO₃@TiO₂ photocatalyst

A PANI-coated heterojunction of WO₃@TiO₂ nanocomposite was fabricated in three stages. The performance evaluation of the prepared photocatalyst for the degradation of ibuprofen was performed under visible light. Characterization of the photocatalyst using X-ray diffraction (XRD) analysis showed that the TiO₂ prepared constituted of the anatase phase. Furthermore, results from in situ XRD analysis of WO₃ show that it consisted of monoclinic and orthorhombic crystalline structures. These phases were not affected by the incorporation of PANI as revealed by XRD analysis. Results from Transmission electron microscopy (TEM) examination showed that sphere-like WO₃ and TiO₂ nanorods of different sizes were prepared In addition, fabrication of a heterojunction of WO₃@TiO₂ wrapped in PANI was shown by TEM analysis. Results from photoluminescence studies indicate that coupling TiO₂ with WO₃ enhanced the charge separation and the degradation performance of the nanocomposite. Supporting the heterojunction on PANI enhanced the degradation efficiency as indicated during the performance evaluation process. Diffuse reflectance spectra (DRS) calculations of the PANI/WO₃@TiO₂ catalysts showed that they can be used under visible light. The experimental results of X-ray Photon Spectroscopy (XPS) analysis showed the presence of elements W, C, O, Ti, and N. Solution pH influenced the degradation process and the maximum degradation efficiency was attained at pH 9. The degradation followed the Langmuir-Hinshelwood kinetic model with a Kinetic constant of 3.5 × 10⁻². The rate of degradation increased in the presence of bicarbonate/carbonate ions and persulfate ions.