Visible light photocatalytic performance of Y-Fe co-doped with SrTiO3 perovskite powder

The Y and Fe doped SrTiO3 compound photocatalytic material (Y(0.03)Sr(0.97)Ti(1-x)FexO(3-delta) (x = 0.03, 0.04, 0.05)) was prepared by Sol-gel method, and the effects of different doped amounts of Fe ions (x=0.03, 0.04, 0.05) on the samples' characteristics were then systematically examined using several techniques. X-ray diffraction (XRD) results indicated the formation of a cubic perovskite structure in all the samples. In accordance with the increased doping amount, the diffraction peak shifted across a large angle. EDS spectra demonstrated the successful doping of both Y and Fe into the SrTiO3 lattice. Scanning electron microscopy (SEM) analysis showed that both the particle size reduction and uniformity of the samples changed with increasing doping amount. The UV-vis diffuse reflectance spectra (DRS) showed that the visible light absorption of pure strontium titanate (STO) was negligible and approached zero. However, there were obvious absorption edges around 400-800 nm for all doped samples. Photoluminescence (PL) results showed both the decreased PL intensity and defective state resulted from the effects of doping materials on SrTiO3. Photocatalytic analysis showed that in the doped samples, methyl orange (MO) exhibited an increased degradation rate under visible irradiation. When the doping content of Fe ions was 0.04 (Y0.03Sr0.97Ti0.96Fe0.04O3-delta), we noted perfect photocatalytic activity which was approximately 2.31 times greater than that of pure SrTiO3 (85% versus 36%). These results well elucidate the photocatalytic performance mechanisms.