LAUSR

Abstract This paper reports the synthesis of pure and Cr-doped TiO 2 nanoparticles with different doping concentrations by using a cost-effective solvothermal method. The as-synthesized nanoparticles were characterized by using X-ray diffraction, transmission electron microscopy and UV–Vis spectroscopy to study their structural and optical properties. The XRD pattern showed the prepared material is pure anatase of the crystalline phase. Using TEM measurement, the average particles size is found to be about 11–13 nm while selective area electron diffraction (SAED) patterns have confirmed the polycrystalline nature of the nanoparticles. The size of the crystallite is observed to be decreased with an increase in dopant (Cr) concentration. UV–Vis absorption spectra showed enhanced absorption in the visible range in accordance with the doping concentration of Cr with a red shift in the absorption edge. The band gap energy of doped nanoparticles decreases in accordance with an increase in dopant concentration due to the reduced particles size. This presented work would be useful to tune the optical properties of doped and undoped metal oxide TiO 2 for its optoelectronic applications.