Synthesis and characterization of catalysts of the type SrTiO₃, SrTi_0,9Fe_0,1O₃, Sr_0,9Ag_0,1TiO₃, Sr_0,9Ag_0,1Ti_0,9Fe_0,1O₃

Full text: Strontium titanate (SrTiO₃) can be classified as a semiconductor with a 'band gap' around 3.2 eV, and has a perovskite type structure A²⁺B ⁴⁺O 3 [1]. In recent years photocatalytic process has been extensively investigated for the degradation of various types of contaminants due to its effectiveness. Therefore it is essential to develop and investigate new systems that allow doping to improve the efficiency of the material. The catalysts were synthesized by the method of polymer precursors [2], which are: titanium isopropoxy, silver nitrate, strontium nitrate, ferric nitrate, citric acid and ethylene glycol. The heat treatment used was: pre-calcination at 300 °C for 30 minutes at a rate of 10 °C.s^-1, then calcination under oxygen atmosphere for 12 hours at 300 °C and rate of 2 °C.s^-1 and finally calcined at 700 °C for 2 hour rate of 10 °C.s^-1. After synthesis the material obtained was characterized by X-ray diffraction (XRD), Infrared Spectroscopy (FTIR), UV-VIS spectroscopy. The perovskite structure of SrTiO₃ and doped systems were identified by record JCPDS 35-0734 as it can identify all systems training phase. Regarding the results of infrared can identify the peak strain and deformation Ti-O with wave number of 588 and 418 cm^-1 respectively and the characteristic peak of CO₃^-2 with wave number 1440 cm^-1. Based on the UV-VIS spectra 'band gap', the doping SrTiO₃ systems has energy in the range 3.2 to 3.4 eV. References: [1]. OLIVEIRA, ALM Synthesis and characterization of powders and thin films SrSn1-xTixO3. 2013. 215 f. Thesis (Dr. in Chemistry). Center of Exact and Natural Sciences, Federal University of Paraiba, Joao Pessoa, 2010. [2] Pechini, MP, Method of preparing lead and alcaline: Earth and titanates niabates and coating method using the same to form a capacitor. U. S. Pat. n. 3.330697 1967. (author)