Photocatalytic degradation of oxytetracycline with praseodymium doped BiYO3 ceramic powders under visible light irradiation

Praseodymium-doped BiYO 3 photocatalysts were synthesized using the Pechini method, using calcination temperatures from 400 to 800 °C for 1 h. The materials were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), UV–visible diffuse reflectance spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The XRD analysis revealed the coexistence of cubic and tetragonal phases in samples calcined at 400 and 600 °C, while the cubic phase was present only in materials heat-treated at 800 °C. SEM and TEM images showed that the synthesized powders consisted of agglomerates of nanocrystals . The band gap of the Pr-doped samples decreased with increasing praseodymium loading, confirming enhanced visible light absorption. Photocatalytic activity was assessed through the degradation of oxytetracycline (OTC) under visible light irradiation . The BiY 0.99 Pr 0.01 O 3 sample calcined at 800 °C exhibited the highest performance, achieving 100 % removal, along with 59.3 % mineralization after 240 min of irradiation. The material demonstrated notable stability in photocatalytic activity over five consecutive reaction cycles. The photocatalytic process was primarily driven by photo-holes, with a low generation of • OH radicals upon irradiation. Stable intermediates were identified by HPLC-MS/MS, leading to the proposal of a degradation mechanism . The Pr-doped material also exhibited high photocatalytic efficiency in removing OTC from tap water at environmentally relevant concentrations.