Preparation of ZnO, ZnFe2O4 and ZnO-SnO2 nanocrystals and investigation of their photocatalytic activity

This paper reports the preparation and investigation of photocatalytic activity of ZnO, ZnFe2O4 and ZnO-SnO2 nanocrystals. Using precipitation and coprecipitation methods, zinc oxide nanocrystals and nano scale binary mixed oxide ZnO-SnO2 were synthesised. Brown nano scale composite zinc ferrite with spinel structure was prepared using co-precipitation method. The products were characterised by powder X-ray diffraction. The crystallite size of the prepared nanocrystals was calculated from diffraction peaks according to Scherrer equation. Their photocatalytic activity was investigated for liquid-phase photocatalytic degradation of erioglaucine herbicide diluted in water under UV light irradiation. It was found that the coupled oxides ZnO-SnO2 mainly consist of nanosized ZnO and SnO2, and they have better photocatalytic activity for degradation of herbicide than ZnO and ZnFe2O4. Also quantum yield and electrical energy consumption amounts in photocatalytic processes were calculated and compared.