Prussian blue/TiO2 nanocomposites as a heterogeneous photo-Fenton catalyst for degradation of organic pollutants in water

Abstract

Nowadays, a lot of research focuses on accelerating Fe^II/Fe^III redox cycles to increase the pseudo first-order rates of the Fenton reaction. Here, Prussian blue/titanium dioxide nanocomposites (PB/TiO₂ NPs) were designed as heterogeneous photo-Fenton catalysts to increase the Fe^II recovery in degrading organic contaminants in water for the first time. The PB/TiO₂ NPs were characterized by various analytical techniques to obtain the optimum ratio of PB and TiO₂ for efficient degradation of organics. The performance of the catalysts was tested by following the removal of rhodamine B dye, salicylic acid, m-cresol, and isophorone under various conditions (pH, ratios of PB and TiO₂, H₂O₂, and temperature). Formation of the intermediates of iron (Fe^II/Fe^III) in the studied system using Mössbauer spectroscopy was explored for the first time and presents important insights into the relevant catalytic phenomena. The generation of ˙OH radicals in the reaction system was identified using electron paramagnetic resonance spectroscopic techniques. Results demonstrated that the developed PB/TiO₂ NPs were stable and could degrade organic contaminants in water efficiently.