Photocatalytic properties of ZnFe-mixed oxides synthesized via a simple route for water remediation

ZnFe photocatalysts have been increasingly investigated for water remediation due to the high demands in this field, such as activity, toxicity, cost, and stability. The presented study was focused on the simple, safe, non-toxic, and eco-friendly synthesis and characterization of ZnFe-mixed metal oxides in correlation with their functional properties. Photocatalytic performance of these materials was evaluated by rhodamine B photodegradation under simulated solar light irradiation. The synthesized mixed oxides contained hexagonal wurtzite ZnO as the predominant phase, whereas, after thermal treatment, the formation of the spinel-structured ZnFe2O4 phase was observed. The photocatalysts with the additional spinel phase and thermally treated at 300 degrees C and 500 degrees C exhibited superior photocatalytic activity probably due to the highest amount of the ZnFe2O4 spinel phase, favourable mesoporous structure, and an optimal energy band gap of similar to 2.30 eV that initiated higher light-harvesting efficiency. The rhodamine B photodegradation followed zero-order kinetics, indicating complete coverage of active sites by the pollutant substrate. Additionally, photocatalysts showed the highest efficiency at the natural pH (6.8), being in accordance with green synthesis principles. Simple, green route assembling synthesis method, high photodegradation efficiency, and good reusability make these ZnFe-mixed oxides great candidates for potential application in practical wastewater treatments.

Automated summary

This study focuses on the simple, safe, non-toxic, and eco-friendly synthesis and characterization of ZnFe-mixed metal oxides, and their correlation with functional properties. The synthesized mixed oxides showed improved photocatalytic activity after thermal treatment, mainly due to the formation of the spinel-structured ZnFe2O4 phase. These photocatalysts also exhibited the highest efficiency at the natural pH (6.8), in accordance with green synthesis principles.