Synthesis and Electrocatalytic Activity of Bismuth Tungstate Bi₂WO₆ for Rhodamine B Electro-Oxidation

Abstract

Herein, we have synthesized different BWO samples at different temperatures and evaluated their electrochemical oxidation of Rhodamine B dye in an aqueous medium. The prepared samples were characterized using X-ray diffraction combined with Rietveld refinements, scanning electron microscope coupled with energy dispersive elemental mapping, and thermogravimetric and differential thermal analyses. All the samples crystallize in the orthorhombic Pca21 structure. The crystallite size increased with temperature. The calculated surface areas from the XRD data ranged from 38 to 7 m2 g−1 for BWO-600 to BWO-900, respectively. The optimal BWO loadings on the GCE electrode were 5 × 10−8 mol cm−2 recording the best electrocatalytic efficiency for RhB electrodegradation in 15 min (100%) in 0.1 M of NaCl. The BWO-600 recorded the best activity compared to other BWO samples. The electrocatalytic activity was explained by the high surface area and small crystallite size compared to the other samples. The BWO-600 showed extended electrode reutilization for up to four cycles of reuse under the reported conditions.

Keywords

• electrochemical degradation
• Rhodamine B
• hydroxyl radicals
• bismuth tungstate
• electrode