Sustainable production of Terminalia arjuna enabled ZnO/MnO nanocomposites via microwave irradiation with improved photocatalytic and antioxidant performance.

In this study, the Green synthesis by microwave irradiation with improved efficiency of nanocomposites to cope up the challenge of aquatic pollution and sustained water resource management. In this formulation, environmentally sustainable ZnO/MnO nanocomposites were synthesized using Terminalia arjuna extract as a natural stabilizing and reducing agent. Comprehensive characterization using XRD, XPS, SEM, TEM, FTIR, and UV-Vis spectroscopy confirmed the formation of well-crystalline nanocomposites with crystallite sizes of 21.34 nm, 17.50 nm, and 19.25 nm for sample (50:50), (70:30), and (90:10) respectively. TEM analysis revealed particle sizes in the range of 23-28 nm, while UV-Vis analysis showed tunable optical band gaps from 2.72 eV to 3.15 eV, reflecting composition-dependent electronic structure. The nanocomposites exhibited outstanding functional performance, with sample (70:30) demonstrating the highest photocatalytic degradation efficiency of methylene blue (97.74%) and significant recyclability (79.48% after repeated use). Antioxidant measurement using the DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay revealed strong radical-scavenging activity, with sample (70:30) again, producing the highest efficiency (91.80%). These results focus the prospective of Terminalia arjuna mediated ZnO/MnO nanocomposites as promising materials for wastewater purification and antioxidant applications, offering a green synthetic route with enhanced multifunctionality.