Microwave-assisted green synthesis of bio-conjugated Mn0.02Co0.03Zn0.05Fe2O4 nanocomposites for magnetically recyclable photocatalytic degradation of methyl orange dye

The increasing discharge of synthetic dyes into aquatic ecosystems has created an urgent need for efficient, eco-friendly
wastewater treatment technologies. In this work, Mn0.02Co0.03Zn0.05Fe2O4
nanocomposites were successfully synthesized via
a microwave-assisted green method using Azadirachta indica (neem) leaf extract as a natural reducing and stabilizing agent.
The structural, optical, morphological, and magnetic characteristics of the prepared nanocomposites were systematically
analyzed using XRD, FTIR, UV–Vis spectroscopy, TEM/HRTEM, and VSM techniques. Photocatalytic activity was assessed
through the visible-light-driven degradation of methyl orange at 463 nm. The Mn/Co co-doped ZnFe2O4
nanocomposites
exhibited superior photocatalytic efficiency, achieving 99.2% dye degradation within 90 min, compared to 88.7% for pristine
ZnFe2O4.
Enhanced performance is attributed to band gap narrowing, improved charge separation, and increased surface
reactivity. Furthermore, the nanocomposites demonstrated adequate magnetic properties for easy recovery and retained over
96% efficiency after three reuse cycles, highlighting their potential for sustainable wastewater remediation applications.