Room-temperature synthesis of silver-based nanoparticle-embedded hydrogel material <i>via</i> catalytic crosslinking for recyclable dye degradation applications

A simple, one-pot, facile room-temperature synthesis method is developed for the fabrication of silver-based nanoparticles embedded within a hydrazone-based hydrogel matrix. The hydrogel matrix is prepared under ambient conditions <i>via</i> acid catalysis by mixing aqueous solutions of the molecular building blocks. The hydrogel network serves as a template for the <i>in situ</i> formation of silver-oxide nanoparticles (Ag₂O NPs) enabling their uniform dispersion and stabilization within the matrix. Ag₂O NPs can subsequently be converted to silver nanoparticles (Ag NPs) by treating them with an aqueous solution of sodium borohydride (NaBH₄). The resulting composite material exhibits rapid catalytic degradation of Congo red (CR) and methyl orange (MO), achieving over 95% degradation efficiency within 5 minutes under ambient conditions in both individual and mixed dye systems. Furthermore, the composite effectively degrades real textile industry wastewater samples. The material also demonstrates excellent reusability, retaining its catalytic performance over multiple cycles without significant loss of activity. These findings demonstrate the potential of <i>in situ</i> synthesized nanoparticle-embedded hydrogel systems as efficient, recyclable, and environmentally friendly platforms for the catalytic degradation of organic dyes.