Synthesis and Catalytic Activity Studies of Silver Nanoparticles Stabilized in Polymeric Hydrogel

This study reports the successful synthesis of silver nanoparticles (AgNPs) stabilized within a crosslinked polymeric hydrogel network. The hydrogel matrix serves as a micro-reactor, effectively controlling the nucleation and growth of AgNPs while preventing their aggregation. The synthesized hydrogel-AgNP composite was comprehensively characterized using UV-Visible Spectroscopy, Fourier-Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The results confirmed the formation of well-dispersed, spherical AgNPs with an average diameter of 10-15 nm embedded within the porous hydrogel structure. The catalytic efficacy of this composite was evaluated using the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction. The reaction followed pseudo-first-order kinetics with a high-rate constant (k) of 0.123 min⁻¹. Furthermore, the hydrogel-AgNP catalyst demonstrated excellent stability and reusability, maintaining over 95% of its initial catalytic activity even after five consecutive cycles. This work presents a simple, cost-effective, and green approach to fabricating a robust nano catalyst with significant potential for applications in environmental remediation and organic synthesis.