Interface-engineered Fe₂O₃-ZnO nanocomposites with ZnFe₂O₄ spinel bridges for efficient OER and antimicrobial...

Efficient and sustainable catalysts for oxygen evolution and antimicrobial applications are important for energy conversion and biomedical technologies. Here we show that interface-engineered Fe₂O₃-ZnO nanocomposites with ZnFe₂O₄ bridges are explored as multifunctional applications. Fe₂O₃ nanoparticles were synthesized via a Bos taurus indicus urine assisted-route and Fe₂O₃-ZnO (10-20 wt%Fe) composites by solvent-free solid-state reaction. XRD/Rietveld, FTIR/Raman, BET, SEM-EDS and XPS confirmed rhombohedral Fe₂O₃, wurtzite ZnO and interfacial ZnFe₂O₄ with modified cation distribution. Fe₂O₃ showed the best oxygen evolution performance, requiring 142 mV to reach 10 mA/cm² with a Tafel slope of 85 mV/dec, high electrochemically active surface area and low charge-transfer resistance. Density functional theory on α-Fe₂O₃ (110) indicated balanced adsorption of *OH, *O and *OOH with *OH → *O as the potential-determining step. Antibacterial assays and anti-inflammatory tests revealed enhanced responses for the composites. This solvent-free strategy yields Fe₂O₃-ZnO-ZnFe₂O₄ architectures that couple efficient alkaline OER with antimicrobial and anti-inflammatory activity.