Photocatalytic evaluation of the magnetic core@shell system (Co,Mn) Fe2O4@TiO2 obtained by the modified Pechini method

TiO2 is a highly active photocatalyst, sometimes obtained with nanometric particle size, which improves its behavior but makes its removal from aqueous media more difficult. To avoid this drawback, this work aims to obtain a photocatalyst easily removable from aqueous media using magnetism. The core@shell system (Co,Mn) Fe2O4@TiO2 was prepared by adding commercial (Co,Mn)Fe2O4 nanoparticles to the titanium polymeric resin synthesized by the modified Pechini method. Optimization of photocatalyst properties was achieved by variation of the TiO2:ferrite ratio, synthesis temperature and time, followed by their evaluation in photodegradation of an azo dye. The highest efficiency was attained when anatase was the major crystalline phase, whereas TiO2:ferrite ratio was limited to 90% to retain the magnetic properties, which enabled its removal from aqueous media using simple magnets. The system (Co,Mn)Fe2O4@TiO2, synthesized with 90% TiO2 and calcined at 500 degrees C for 8 h, presented a discoloration of 76.3% after 16 h of exposure to UV light.