EDTA mediated microwave hydrothermal synthesis of WO₃ hierarchical structure and its photoactivity under simulated solar light

In this paper, we report a facile microwave hydrothermal synthesis of WO₃ hierarchical structure in presence of disodium salt of ethylenediaminetetraacetic acid (EDTA) as a complexing agent and its photoactivity for the degradation of rhodamine B (Rh B) under simulated solar light irradiation. The synthesized WO₃ samples were structurally, morphologically and optically characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and Brunauer-Emmett-Teller (BET) surface area analysis. The result revealed that the addition of EDTA leads to the controlled aggregation of WO₃ nanoparticles having high crystallinity with monoclinic structure and creates oxygen vacancy in the WO₃ lattice. Moreover, at high concentration of EDTA, cauliflower like hierarchical structure was formed when the optimum concentration of EDTA reaches to 0.5 mol% at pH 6 and exhibited best photoactivity for the Rh B degradation. These results indicate that the WO₃ hierarchical structures with oxygen vacancies are potential materials for effective mineralization of Rh B, one of the hazardous pollutants.