Cr-Doped Tio2: A Study on Optical and Photocatalytic Enhancement for Solar Wastewater Treatment

Abstract

To investigate the effect of Cr doping on the optical, structural, and photocatalytic properties of TiO2, Cr-doped TiO2 nanoparticles were synthesized using the single-step sol-gel method. Mixed anatase and rutile phases of TiO2 was confirmed by XRD, with no emergence of additional peaks indicating successful Cr doping. In addition, Cr doping resulted reduction in the average crystallite size of the TiO2, from 64.34 to 13.61 nanometers. FTIR analysis was used to identify the chemical linkages (Ti-O) and (O-H) present in the products. The energy band gap acquired from UV-Vis absorbance data and determined by the tauc plot shows a progressive drop from 3.22 eV to 2.84 eV with Cr doping. The photocatalytic activity of Cr-doped TiO2 nanoparticles was evaluated by degrading methylene blue dye under conditions of visible direct sunlight. The findings showed that Cr-doped TiO2 (39.77%) performed significantly better as a photocatalyst than undoped TiO2 (6.40%) in 120 minutes.

Keywords: Photocatalysis, Cr-doped TiO2 nanoparticles, Methyelen Blue (MB), water pollution