Effect of single doping and dual doping with Mn and Fe on the photocatalytic activity of TiO2 nanoparticles

Abstract

Pure, Fe-doped, Mn-doped, and Fe/Mn-co-doped titanium dioxide nanoparticles were synthesized by hydrothermal method at 180 °C for 24 h to enhance the photocatalytic activity for degradation of organic and pharmaceutical pollutants in wastewater. The prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy (FE-SEM), UV-visible spectrophotometer, zeta potential, and Fourier transform infrared spectroscopy. Every sample has anatase phase and tetragonal structure according to the pattern of XRD. It was noted that titanium dioxide when doped with manganese and iron, exerts a substantial influence on the crystallite size, lattice parameter, and energy band gaps of all specimens. Every sample has an anatase phase and tetragonal structure according to the pattern of XRD. The TiO₂ pure and doping TiO₂ with metal ions can hinder the particle’s crystal growth. An FE-SEM image presents homogeneous morphology with a spherical form. The calculated optical bandgap values derived from optical measurements are situated in the range of 3.2–2.2 eV. The TiO₂ and doped TiO₂ system has shown to be highly efficient in promoting the degradation of organic and pharmaceutical pollutants in wastewater as detected by a set of techniques such as high-performance liquid chromatography (HPLC) and Gas chromatography (GC). All the specimens have high photocatalytic activity, but the Fe: Mn (3%, 3%) co-doped TiO₂ showed the highest photocatalytic activity against degradation of organic and pharmaceutical pollutants. Also, our study has proven that a single-doped and co-doped TiO₂ catalyst is an effective and promising method in water treatment.