Mixed cobalt-copper ferrite-type materials: synthesis and photocatalytic efficiency in degradation of Reactive Black 5 dye under UV-light irradiation

K Zaharieva, K Milenova, V Rives, R Trujillano, Z Cherkezova-Zheleva, A Eliyas, M Tsvetkov, B Kunev, I Mitov
Mixed cobalt-copper ferrite-type materials having different compositions were prepared using a coprecipitation technique and mechanochemical or microwave treatment. Various physicochemical methods, such as powder X-ray diffraction, Mössbauer and FTIR spectroscopy, single point BET method, porosity investigations, and temperature-programmed reduction, were used for characterization of the obtained ferrite-type samples. The photocatalytic activities of the so synthesized cobalt-copper
more » ... materials were examined in oxidative degradation of Reactive Black 5 (RB5) dye as model contaminant in aqueous solution under UV-A light illumination. Photocatalytic activity tests established that microwave treatment of coprecipitated Co 0.25 Cu 0.25 Fe 2.5 O 4 sample leads to a higher degree of degradation of RB5 dye (98%) compared to that of coprecipitated (96%) and mechanochemically treated (73%) materials. Mechanochemical treatment enhanced the conversion degree of RB5 dye after 120 min of illumination: 77 and 78% for Co 0.5 Cu 0.5 Fe 2 O 4 and Co 0.4 Cu 0.1 Fe 2.5 O 4 , respectively, compared with matching coprecipitated samples (48% and 52%), accordingly. An enhancement of photocatalytic efficiency of prepared cobalt-copper ferrites upon decreasing the cobalt content was established. The photocatalytic properties of obtained mixed cobalt-copper ferrite-type samples were affected by the degree of incorporation of metal ions in the magnetite-type structure and by applied preparation methods.