Hydrothermal synthesis and characterization of carbon-doped TiO2 nanoparticles*

Abstract

We report the hydrothermal growth of pure and doped TiO2 nanoparticles with different concentrations of carbon. The microstructure of the as-synthesized samples is characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), and Raman spectroscopy to understand the structure and composition. The XRD patterns confirm the formation of anatase phase of TiO2 with the average crystallite size is calculated to be in the range of 13 nm to 14.7 nm. The functional groups of these nanostructures are characterized by Fourier transformed infrared (FT-IR) spectroscopy, which further confirms the single anatase phase of the synthesized nanostructures. UV-visible absorption spectroscopy is used to understand the absorption behavior, which shows modification in the optical bandgap from 3.13 eV (pure TiO2) to 3.74 eV (1.2 mol% C-doped TiO2). Furthermore, the Ti3+ centers associated with oxygen vacancies are identified using electron paramagnetic resonance spectroscopy (EPR).