Facile synthesis of nTiO2 phase mixture: Characterization and catalytic performance

Abstract In this paper, we report the synthesis of titanium dioxide nanoparticles (nTiO 2 ) by the sol-gel method followed thermal treatment at 100, 300, 500 and 700 °C. The structural characterization by XRD and Rietveld refinement method confirmed the mixture of phases in the synthesized nanoparticles. Raman spectroscopy corroborated the presence of phase mixing, identifying polymorphs of TiO 2 . The nanoparticles exhibited spherical shape with dense appearance when investigated by FE-SEM. The band gap values obtained by diffuse reflectance resulted in the decrease of E gap values with the increase of temperature. The catalytic study on the discoloration of the MB and RhB dyes showed great performance for nanoparticles obtained at 500 °C. We present the gradation ratio (%), apparent velocity constant (Kapp) and half-life time (t 1/2 ) referring to 99.8% (AM) and 100% (RhB), 50.03 × 10 −3  min −1 (AM) and 101.1 × 10 −3  min -1 (RhB) and 13.85 min (AM) and 6.85 min (RhB), respectively.