Effect of La on structural and photocatalytic activity of SnO2 nanoparticles under UV irradiation

This study was carried out to analyze and evaluate the change in structural, optical and photocataylitic properties by doping of La in SnO2. In present work, pure and La doped SnO2 nanocrystalline powders have been synthesized by a chemical micro emulsion method. Different concentration of La was used. Samples were annealed at different temperature (500 degrees C and 850 degrees C). Morphology, structural, electrical and optical properties were investigated. Different tools such as X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Fourier Transformation Infrared Spectroscopy (FIIR), UV-vis and Near Edge X-ray absorption spectroscopy (NEXAS) were used. Results confirmed the formation of single phase rutile type tetragonal structure and also the variation in the lattice parameters have been observed which confirm the incorporation of La in SnO2 lattice. The average crystalline size was diminished with doping of La. FESEM reveals the spherical shape of particles with a size ranging from 10 to 20 nm. However, agglomeration of the particles has also been observed. Chemical bonding and presence of compounds are revealed by using FTIR and XANES, respectively. In ultraviolet (UV) light irradiation, photocatalytic activities of the samples toward methyl orange were investigated. 5.0 mol% La-doped SnO2 showed the best photocatalytic activity and which were found to Exhibit 2.75 times higher activity than other prepared samples.