LAUSR

Abstract In this work the nanocrystalline particles of BiFO3 co-doped with ytterbium and cobalt Bi1-xYbxFe1-xCoxO3 (x = 0.0, 0.02, 0.04, 0.06, 0.08) were synthesized via sol-gel method. The phase purity and crystallinity of the synthesized particles were examined by X-ray diffraction (XRD) technique. The values of the diffraction peaks match precisely with the standard data (JCPDS card no.-71-2494). XRD data also ensures the formation of rhombohedral symmetry of R3C space group. Raman spectra over the frequency range of 800–1600 cm−1 have been systematically investigated with different excitation wavelengths. For determining vibrational modes of the doped nanoparticles, Raman scattering spectra at excitation wavelengths λ = 532 nm was recorded. FESEM images reveal the fact that, x = 0.02 doping significantly reduces the grain size resulting high surface area for active sites.X-ray photoelectron spectroscopy (XPS) was also carried out to estimate the compositions and the valence states of elements in Bi1-xYbxCoxFe1-xO3 (x = 0.04, and 0.06) nanoparticles. The substitution of Yb3+ and Co2+ ions in BFO nanocrystalline samples, improves the magnetic and photocatalytic properties. The entire range of visible light wavelength absorption is observed in all the synthesized nanoparticles and were analysed by UV–Visible absorption spectroscopy. The energy band gap was found to be ~2.30 eV for pure BFO, which get altered by Yb3+ and Co2+ substitution and found to be ~1.88 eV in case of Bi0.94Yb0.06Fe0.94Co0.06O3 nanoparticle. The photocatalytic properties get enhanced with the substitution of Yb3+and Co2+ in BFO, that may be due to change in energy band gap and formation of trapping sight, which results into increase in the number of electron hole pair and hence improve the photocatalytic properties.