Superior optical properties of Fe3+-W18O49 nanoparticles prepared by solution combustion synthesis

Modification by metal-doping allows the design of new nanomaterials with enhanced optical properties. In this paper, the photocatalytic effects of Fe3+-doped W18O49 nanorods prepared by solution combustion synthesis were studied for the first time. The Fe3+-doped W18O49 powders were investigated by X-ray diffraction, high-resolution transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy. The powders were well-crystalline with diameters ranging from 50 nm to 250 nm and the length decreasing from more than 10 mm to 4 mm on average. The photoluminescence (referred to as PL here after) spectrum showed that the emission intensity increased with increasing Fe3+ doping, suggesting that more defects were generated. Moreover, this novel composite catalyst displayed excellent photocatalytic efficiency towards the degradation of organic compounds in aqueous media under UV-visible light irradiation. In particular, 0.5 wt% Fe3+-doped W18O49 had the best photocatalytic efficiency. This improvement was mainly attributed to the synergistic effect between Fe3+ and W18O49 nanopowders and the defects in the nanostructure caused by doping.