Abstract
Bioaccumulation of synthetic organic dyes in wastewater as a result of industrial effluents is a growing concern. These dyes are known to be resistant to conventional biological water treatment processes. This has compelled the search for more effective and sustainable water treatment procedures. This work investigates the use of visible light active WO3-based photocatalysis as a possible technology for the removal of these dyes. Tungsten trioxide (WO3) nanoparticles were synthesized via a facile chemical precipitation method. These particles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) to confirm the crystallinity, elemental composition, structural morphology, and specific surface area. X-ray diffraction characterization revealed that the nature of the material was biphasic (WO3/WO3.0.5H2O). BET surface area analysis showed that upon calcination, the surface area increased from 0.1611 to 25.4 m2/g. Preliminary experiments showed that the degradation of Rhodamine B using WO3-based particles was highly pH dependent, with rapid degradation occurring under alkaline conditions. A pH of 9.5 was chosen for this study. A 96.1 % degradation efficiency of Rhodamine B was achieved at an optimum catalyst loading of 5 g/L after 4 h of irradiation.
