Fabrication of poly (N-vinylcaprolactam-co-acrylic acid)-silver nanoparticles composite microgel with substantial potential of hydrogen peroxide sensing and catalyzing the reduction of water pollutants

Herein, we report the synthesis of poly(N-vinylcaprolactam-co-acrylic acid) microgel via free radical polymerization and its fabrication with silver nanoparticles. The fabricated microgels were applied for sensing and catalytic applications. The identification of functional groups in the pure and composite microgel was carried out by Fourier transform infrared spectroscopy. Dynamic laser light scattering studies confirmed the particulate nature of synthesized microgels with average diameter of ~& nbsp; 99 nm at pH 7. Thermal stability was checked with Differential Scanning Calorimetry and Thermogravimetric Analysis. X-ray diffraction pattern showed the amorphous nature of pure microgel, and face centered cubic geometry of incorporated AgNPs. The optical properties were evaluated by employing UV-visible spectroscopy. A clear observation of a red shift in the wavelength corresponding to localized surface plasmon resonance (lambda(SPR)) of AgNPs with a gradual increase in pH of medium ratified that the system is a potential candidate to be used as a pH sensor. The as-prepared composite microgel showed good sensing ability for hydrogen peroxide. Moreover, composite microgel was found to be an efficient catalyst for 4-Nitrophenol, 2Nitrophenol and 2-Nitroaniline reduction to their respective amino compounds. Highest catalytic rate constant (kappa(app)) by pseudo-first order kinetics was measured for 4-Nitrophenol as 1.03 min(-1) at 323 K. In addition, fabricated composite microgel was also found to be a good catalyst for organic dyes, Methylene blue (MB) and Methyl Orange (MO) degradation.(c) 2022 Elsevier B.V. All rights reserved.