Eco-Friendly Mechanochemical Fabrication of Polypyrrole/Ag-ZnO Heterostructures for Enhanced Photocatalytic Degradation of Methyl Orange

Abstract

A Ppy/Ag-ZnO catalyst was successfully synthesized at room temperature using a novel, green methodology. It involves a mechanically assisted metathesis reaction. The Ppy/Ag-ZnO catalyst was analyzed via X-ray diffraction Technique (XRD), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), UV–visible spectroscopy, Brunauer–Emmett–Teller (BET), and zeta potential. Debye Scherrer’s calculation suggested a crystallite size of 2.30 nm for Ppy/Ag-ZnO nanocomposite. SEM confirmed the production of aggregated particles with an average size of 2.65 μm, endorsing the -ve zeta potential value (−6.78 mV) due to the presence of Van der Waals forces among the particles of Ppy/Ag-ZnO. DSC confirms that the strong interfacial interaction between Ag-ZnO and the polar segments of Ppy is responsible for the higher Tg (107 °C) and Tm (270 °C) in Ppy/Ag-ZnO. The surface area and average pore size of Ppy/Ag-ZnO catalyst were determined to be 47.08 cm3/g and 21.72 Å, respectively. Methyl orange (MO) was used as a probe in a photocatalytic reaction of fabricated material, which demonstrated exceptional efficiency, exhibiting a removal rate of 91.11% with a rate constant of 0.028 min−1. Photocatalytic degradation of MO was shown to follow pseudo-first-order kinetics.