Preparation and Characterization of the MMT@Fe₃O₄@Ag Nanocomposite for Catalytic Degradation of Methyl Yellow: Reaction Parameters and Mechanism Based on the Artificial Neuron Network

The montmorillonite@iron oxide@silver (MMT@Fe₃O₄@Ag) nanocomposite, which is recyclable and exhibits high catalytic activity, was evaluated for the degradation of methyl yellow (MY), a carcinogenic azo dye. For this purpose, MMT@Fe₃O₄ was first synthesized via the coprecipitation method and then Ag was doped to MMT@Fe₃O₄ via the chemical reduction method. MMT, MMT@Fe₃O₄, and MMT@Fe₃O₄@Ag were characterized by various techniques including scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, and thermal gravimetric analysis. The results illustrated that MMT@Fe₃O₄@Ag exhibited a higher catalytic ability than MMT@Fe₃O₄ toward decolorization of MY with a degradation efficiency of 100% in 10 min at pH 7.1 in the presence of sodium borohydride (NaBH₄). Further, some parameters like the amount of NaBH₄, initial dye concentration, and pH were also studied to determine optimum reaction conditions. MMT@Fe₃O₄@Ag could be easily separated and recycled from the reaction medium using an external magnet. Thus, the Ag-doped MMT@Fe₃O₄ nanocomposite proved to have good catalytic activity, high MY degradation rate and reusability, and easy separation and simple synthesis method. These properties make it a promising catalyst for the treatment of wastewater containing organic pollutants. In addition, artificial neural network (ANN) simulation, which is a mathematical model with an artificial intelligence algorithm, was used for the degradation process. This model was evaluated with the parameters used in the experiment as the input and output layers. Last, the degradation of MY with the synthesized catalyst into different products was demonstrated by high-performance liquid chromatography (HPLC) analysis.