Mechanism of simultaneous photocatalytic degradation of Rhodamine B and Cr(VI) under visible light using WO₃ nanotubes

A hydrothermal method was used to synthesise WO 3 nanotubes, which were analysed using transmission electron microscopy (TEM), x-ray diffraction (XRD), Raman, and UV–Vis spectroscopy for morphological, structural, and optical properties. TEM revealed nanotubes several micrometers long with a diameter of 10–15 nm. These nanotubes effectively removed Rhodamine B (RhB) and Cr(VI) under visible light. The high photocatalytic efficiency of obtained WO 3 material was attributed to the large surface area provided by the unique configuration in the form of nanotubes. The study identified reactive species through scavenger tests and proposed a photocatalytic mechanism. This approach offers efficient photocatalysts for the simultaneous sunlight-driven degradation of organic and inorganic pollutants in wastewater.