Harnessing the interfacial charge transfer in Mn-doped γ-Fe2O3@ZnO heterojunction for broad spectrum photocatalytic degradation of organic dyes

Developing affordable, sustainable, and environmentally friendly water remediation strategies is inevitable to achieve water security worldwide. To align with these challenges, this investigation successfully synthesized lowcost Mn-doped iron oxide and its heterojunction with Zinc Oxide (ZnO) as an efficient recovery mechanism for deteriorated water. Comprehensive characterization of Mn-doped gamma-Fe2O3@ZnO heterojunction was performed using X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy, Energy dispersive X-ray, and Photoluminescence analysis. The electrical behaviors of all samples were characterized using Electrochemical impedance spectroscopy and Mott-Schottky analysis. This heterojunction showed distinct structural features along with a bandgap energy of 2.61 eV, confirming the formation of a heterojunction. The effectiveness of this heterojunction was assessed using Congo red (CR) and Crystal violet as model pollutants. The photodegradation capability using a small amount of as-synthesized photocatalyst (10 mg) reached 90.8 % for CR and 90.5 % for CV under natural sunlight for a duration of 105 min. The key findings of this report clearly demonstrated the effectiveness of the interfacial charge transfer mechanism of Mn-gamma-Fe2O3@ZnO heterojunction towards the degradation of organic water contaminants.