Degradation Of Methylene Blue Dye Using Biologically Synthesized of Mn ₃ O ₄ : Ag Nanocomposites by Thyme Leaves Extract

ABSTRACT In this study, Mn 3 O 4 :Ag nanocomposites were successfully synthesized via an eco‐friendly green synthesis approach using Thymus vulgaris leaf extract as a natural reducing and stabilizing factor. Mn 3 O 4 :Ag nanocomposites were thoroughly characterized using multiple analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), UV–vis Spectroscopy, Scanning Electron Microscopy (SEM), X‐ray Diffraction (XRD), and Energy‐Dispersive X‐ray Spectroscopy (EDX). The nanocomposites were prepared in three different molar ratios of Mn 3 O 4 :Ag (1:0.25, 1:0.5, and 1:1) and evaluated for their photocatalytic performance in the degradation of Methylene Blue (MB) dye under visible light. Among the tested ratios, 1:0.5 compositions exhibited the highest photocatalytic activity with an initial degradation efficiency of 91%. The optimization parameters, including dosage, solution pH, temperature, and active species trapping experiments, revealed that the nanocomposite achieved up to 99% MB degradation within 180 min, at neutral pH 7, a temperature range of 25–50°C, and using only 20 mg. Additionally, the material retained high efficiency after seven reuse cycles, maintaining 97% activity, indicating outstanding stability and reusability. This eco‐friendly approach offers a viable substitute for conventional wastewater treatment methods, combining green chemistry with effective photocatalysis