Photodegradation of 17 α-methyltestosterone using TiO2 -Gd3+ and TiO2-Sm3+ photocatalysts and simulated solar radiation as an activation source

Abstract

According to the search in the state of the art, no antecedents were found in which photocatalytic degradation of 17α-methyltestosterone (MT) hormone has been carried out using doped-TiO2. Nor have the transformation products formed during the heterogeneous photocatalysis (FH) been identified. Therefore, in this study we analyzed the photocatalytic degradation of the MT in aqueous solution, using doped TiO2 with Sm3+ or Gd3+ at 0.3 and 0.5 %wt. Thermal treatment temperature (500 °C and 800 °C) and MT (20 mgL−1) mineralization were also studied. All photocatalysts were synthesized using the sol-gel method and characterized by X-ray Diffraction (XRD), Specific Surface Area (BET), Ultraviolet–visible Spectroscopy (UV–vis), High-Resolution Transmission Electron Microscope/Energy-Dispersive X-ray analysis (HRTEM/EDS) and, X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL). MT mineralization was followed by a total organic carbon analyzer (TOC). The route of the photocatalytic mineralization of the hormone was obtained from the analysis of intermediate compounds determined by high performance liquid chromatography coupled to mass spectrometry (LC-TOF-MS). The results showed that TM and its transformation products were not degraded by photolysis. However, the degree of mineralization of the hormone was greater when the photocatalytic process was used. The photocatalytic efficiency was related to the dopant concentration, dopant type and thermal treatment. Therefore, Sm (0.3%)/TiO2 calcined at 500 °C showed the best performance for photocatalytic mineralization of MT.