Simultaneous Fenton–Photocatalytic Reactions through a New Single Catalyst (Nano ZnO₂ /Fe²⁺) for Dye Degradation

Fenton catalysts, H2O2/Fe2+, have been known for a long time and are employed for environmental remediation through the Fenton mechanism involving reactive oxygen species (ROS). Storage and transportation of H2O2 limits its applications. Semiconductor photocatalysts have also been explored extensively toward environmental remediation involving ROS through irradiation of light. There is a need to develop a single catalyst that combines both Fenton and photocatalytic mechanisms. With this objective, we designed and synthesized a new catalyst based on ZnO2/Fe2+ that is useful for environmental remediation. This single catalyst that exhibits simultaneous Fenton–photocatalytic reactions produces H2O2 in situ from the peroxide of ZnO2 (solid), thus avoiding storage and transportation. This new catalyst works in the dark (Fenton-like), under visible light (photo-Fenton) and UV light (photocatalytic) mechanism. Furthermore, the performance is better than the known Fenton catalyst.