Catalytic degradation of various dyes using silver nanoparticles fabricated within chitosan based microgels

Precipitation polymerization method was used to synthesize chitosan based poly[chitosan-N-isopropylmethacrylamide-acrylic acid] [P(CS-NI-AA)] microgel particles. Synthesized P(CS-NI-AA) microgel particles were utilized as micro-reactors for the fabrication of silver nanoparticles (AgNPs) inside the structure of microgels through chemical reduction of Ag⁺ ions using NaBH₄ as reducing agent. P(CS-NI-AA) and Ag-P(CS-NI-AA) systems were analyzed using various characterization techniques like scanning electron microscopy (SEM), ultraviolet-visible (UV-visible) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Catalytic activity of Ag-P(CS-NI-AA) for individual and simultaneous degradation of various dyes like methylene blue (MB), Congo red (CR), brilliant blue (Bb), methyl orange (MO) and Rhodamine B (RB) was investigated in aqueous phase using NaBH₄ as reductant. The Pseudo 1st order rate constant (k₁) for dyes degradation were evaluated. The Ag-P(CS-NI-AA) hybrid system was observed to be efficient, low-cost and stable catalyst for quick degradation of dyes.