Rare-earth-doped tungsten oxide microspheres with highly enhanced photocatalytic activites

Rare-earth-doped WO2.72 microspheres (RE-WO2.72 MSs) have been successfully synthesized by using a facile solvothermal route with tungsten salt as precursor, RE (RE=Ce, La, and Y) metal salts as dopants, and ethanol as solvent. Results of X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), and energy dispersive spectroscopy (EDS) showed that the solvothermal process allowed for the homogeneous doping of WO2.72 while maintaining the original crystal structure. The RE doping could effectively engineer the bandgap of WO2.72, which could not only enhance the light-harvesting ability but also deduce up-shift of both the conduction band and valence band. Compared to the undoped WO2.72 nanorods (NRs), the RE-WO2.72 MSs exhibited highly enhanced photocatalytic properties for the degradation of methylene blue (MB) under full spectrum light irradiation. This work provides a versatile strategy for the synthesis of RE-doped tungsten oxides and can be extended to the doping of other oxide semiconductors.