Fabrication of efficient and easily recyclable silver nanoparticle–anionic polymer hydrogel composite catalyst for rapid degradation of water pollutants

In this study, a porous three-dimensional polymeric network of poly(3-sulfopropyl methacrylate) [p(SPMA)] is prepared and embedded with silver nanoparticles (Ag NPs) to design a nanocomposite catalyst. Analytical techniques including X-Ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX), Rheology, and UV–visible spectroscopy are used to investigate the composition and morphology of the prepared nanocomposite catalyst. The fabricated p(SPMA) hydrogel exhibits a hydrophilic character, with a % swelling of 1974 in an aqueous medium. The porosity of the nanocomposite catalyst is corroborated using SEM, while the skeleton of p(SPMA) and the embedding of the AgNPs are affirmed using EDX. The catalytic performance of the synthesized nanocomposite catalyst is analyzed in the chemical reduction of two different dyes, methylene blue (MB) and methyl orange (MO), and two different nitroaromatic compounds, 4-nitrophenol (4-NP) and 4-nitroaniline (4-NA). The apparent rate constant (k_app) of the catalyst is found to be 0.365x10^-2, 1.059x10^-2, 0.159x 10^-2, and 0.581x10^-2 sec^-1 for 4-NA, 4-NP, MO, and MB, respectively. The synthesized nanocomposite catalyst is recycled ten times in succession through the simple, quick, and effortless process of filtration via a plankton cloth filter, and it is found that the catalyst retains 70% of its activity in the tenth cycle.