Structural, Optical, Thermal and Photocatalytic Dye Degradation Properties of BiFeO3-WO3 Nanocomposites

摘要

In the present work, nanocomposites of BiFeO3-WO3 (BFO-WO3) have been successfully synthesized for the first time by a single step sol-gel method. The main objective lies in enhancing the photocatalytic activity of BiFeO3 by modifying it with a WO3 matrix. Powder x-ray diffraction studies on BFO-WO3 confirm the presence of the monoclinic character of WO3 along with rhombohedral BFO. In addition, elemental mapping using energy dispersive x-ray analysis ascertains the existence of tungsten ions in the BFO matrix. Field emission scanning electron microscopy analysis on pure and nanocomposites depicts the distinct morphologies of the nanoparticles upon modification of BFO with WO3. From the UV-Vis-NIR spectrum, it has been noticed that there is a reduction in the band gap energy from 1.8 eV (BFO) to 1.5 eV (BFO-WO3) suggesting the increase in the absorption of a visible portion of light upon loading of WO3 in BFO. Thermogravimetric analysis/differential thermal analysis trace of BFO-WO3 nanocomposites shows that there is a suppression of the multiferroic character of BiFeO3, when it is modified with WO3. However, the photodegradation of methylene blue using BFO-WO3 nanoparticles found to have been enhanced to 91%. The increase in dye removal property may be due to the fact that the higher surface area of nanocomposites due to the incorporation of WO3 particles. The other significant results have been discussed in detail.