Photocatalytic degradation of tetracycline by Fe-doped mechanically activated SrTiO3 powders in aqueous solution

Abstract

Mechanically activated strontium titanate (SrTiO3) powders with various iron (III)oxide (Fe2O3) doping levels (1.5, 3, and 6 wt%) were prepared by solid state method. Due to the possibility of iron ion incorporation in SrTiO3 onto Sr2+ and/or Ti4+ sites a detailed analysis of the influence of dopants on the microstructure, morphology, optical properties and photocatalytic activity was conducted. The XRD analysis showed that iron was incorporated into the lattice of SrTiO3 particles. In the case of a lower concentration of dopant (1.5 wt%), there was a significant relative contribution of the substitution of Sr2+ ions by Fe3+ ions. In contrast, substituting Ti4+ ions with Fe3+ ions dominated samples with an increased concentration. Optical measurements indicated a shift of the absorption edge to higher values of wavelengths where the lowest value of the band gap (Eg=1.85 eV) was for the longest activation time (120 min) and the highest weight percentages of dopant (6 wt%). All samples have degraded tetracycline (TC) where degradation increases with longer irradiation time and dopant concentration. The highest degradation at 43 % was for 120 min activated sample with 6 wt% of Fe2O3.