Fast and highly efficient catalytic degradation of dyes using κ-carrageenan stabilized silver nanoparticles nanocatalyst

•κ-Carrageenan gum stabilized AgNPs nanocatalyst prepared via a greener approach.•Physicochemical properties of nanocatalyst were investigated.•κ-CG-s-AgNPs are spherical in shape, with average size of 12 nm.•Nanocatalyst exhibit fast and superior catalytic performance against organic dyes•The catalyst showed excellent stability and good reusability. Herein, we have reported the synthesis of silver nanoparticles (AgNPs) nanocatalyst by using high-molecular-weight κ-carrageenan. The developed methodology was rapid, facile, ecofriendly and cost effective, which did not require subsequent processing for reduction or stabilization of AgNPs. The physico-chemical characterization was performed by FT-IR, zeta potential (ζ), XRD, TGA, XPS and TEM techniques. The TEM results revealed that the AgNPs were spherical in shape, with average size of 12 nm, and face centered cubic (FCC) structure throughout the polymer matrix and was stable without any protecting or capping reagents over two months. The synthesized nanocatalyst exhibited high catalytic degradation and mineralization of industrially important organic dyes such as Rhodamine B, and methylene blue, with a degradation efficiency of ∼100 % in a very short interval. The fast kinetics of the dye degradation is quite unique compared to the reported literatures based on various catalyst systems where slow kinetics was reported.