Revealing improved photocatalytic decomposition of fluoroquinolone antibiotic over hydrothermally grown perovskite SrTi1-xFexO3 nanostructures

Abstract

This research focused on the development and evaluation of Fe-doped SrTiO₃ photocatalysts, labeled as SrTi_1-xFe_xO₃, for the degradation of the antibiotic ciprofloxacin under visible light. The photocatalysts were synthesized via a hydrothermal method, with Fe doping levels ranging from x = 0.005 to x = 0.10. Characterization techniques confirmed the successful incorporation of Fe into the SrTiO₃ lattice, primarily at interstitial sites, leading to a gradual bandgap reduction from 3.20 eV (undoped SrTiO₃) to 2.51 eV (x = 0.10). This narrowing significantly enhanced visible light absorption, improving the photocatalytic activity under the visible spectrum. The photocatalytic activity confirmed that SrTi_1-xFe_xO₃, particularly at a doping level of x = 0.01, exhibited superior activity in degrading ciprofloxacin (78.30 % and k_app of 9.79 × 10^–3 min^–1) compared to the undoped SrTiO₃ (64.25 % and k_app of 2.47 × 10^–3 min^–1) under 420 nm visible region. This improvement was attributed to enhanced charge carrier dynamics, facilitated by the introduction of Fe³⁺/Fe⁴⁺ redox pairs and the creation of intermediate energy levels within the bandgap. While higher Fe doping levels (x = 0.05 and x = 0.10) led to reduced photocatalytic efficiency due to the formation of recombination centers, the overall findings highlight the potential of SrTi_1-xFe_xO₃ as a promising photocatalyst for environmental applications. The study emphasizes the importance of optimizing Fe doping concentrations to maximize photocatalytic performance and suggests that further exploration of doped SrTiO₃ materials could lead to even more efficient solutions for the degradation of persistent pharmaceutical contaminants in water systems.