Structural refinement and photocatalytic activity of Fe-doped anatase TiO2 nanoparticles

Colloidal iron-doped (0.0–3.0 mol%) TiO2 nanoparticles have been synthesized using sol–gel method and characterized by thermogravimetric analysis, powder XRD, IR spectroscopy, Raman spectroscopy, and transmission electron microscopy (TEM). The characteristic features of nanocrystalline TiO2 in tetragonal anatase phase were confirmed by powder XRD studies with Rietveld refinement. Rietveld refinement data gave 2.59, 3.21 value of RB for pure TiO2 and 3.0 mol% Fe:TiO2 nanoparticles, respectively. Raman bands at 639 cm−1, 517 cm−1, and 395 cm−1 further confirmed the pure anatase phase in all samples. TEM pictures revealed the non-spherical nanoparticles having sizes in between 7 and 14 nm. Surface area and pore volume for the samples were in the range of 150–87 m2/g and 0.35–0.21 cm3/g, respectively. The magnetic and optical properties of the nanoparticles were investigated by using SQUID magnetometer and UV–vis spectroscopy. The undoped titania nanoparticles were diamagnetic; whereas all doped titania samples were paramagnetic. The optical band gap of titania nanoparticles were found to decrease with the increase in iron content in host lattice. The photocatalytic performance of the iron-doped TiO2 nanoparticles for the conversions of p-nitrobenzaldehyde to p-nitrobenzoic acid as well as photodegradation of Rhodamine 6G was also investigated.