The influence of the coprecipitation synthesis methods on photodegradation efficiency of ZnFe based photocatalysts

Abstract

Organic dye pollutants that are progressively used in modern chemical industries, emerged as a major source of water contamination. A promising eco-friendly and simple approach to water purification is the heterogeneous photocatalytic process that uses various metal oxide semiconductors in the presence of light, initiating the oxidation-reduction reactions resulting in dye degradation. The aim of this study was to investigate the influence of coprecipitation synthesis methods on photodegradation efficiency. The ZnFe based photocatalysts were synthesized using two different methods: low (LS) supersaturation and high (HS) supersaturation coprecipitation and thermally activated at 100, 300, 500 and 700ºC. Structural and textural characterisation were carried out and their efficiency in methylene blue photodegradation test reaction was studied. LS samples treated at 100 and 300ºC exhibited very low photodegradation efficiency (less than 10 %) when compared to HS samples treated at the same temperatures (75 and 85 %). The efficiency of LS 500 and LS 700 samples improved (67 and 75 %) with the increase in thermal treatment temperature and the photodegradation efficiency difference between LS and HS samples decreased. Such behaviour of LS and HS samples could be explained by structural and textural properties that originated from different synthesis methods.

Keywords

• mixed metal oxides
• photocatalysis
• methylene blue