Effective degradation of rhodamine B and Congo red dyes over biosynthesized silver nanoparticles-imbibed carboxymethyl cellulose hydrogel

Abstract

The carboxymethyl cellulose (CMC)-based hydrogel was synthesized by grafting of poly(acrylic acid) chains in the presence of ammonium persulphate–N,N′-methylenebisacrylamide (MBA) as initiator–cross-linker system. Silver nanoparticles (Ag NPs) were biosynthesized using aqueous extract of Diospyros discolor leave extract and polyvinyl alcohol and are then imbibed in the hydrogel. Synthesized Ag NPs- and Ag NPs-imbibed CMC hydrogel was examined through UV–Vis spectroscopy and zeta potential, and size and morphology were confirmed by TEM and FTIR techniques, respectively. The Ag NPs-imbibed CMC hydrogel acts as an effective adsorbent for the removal of harmful dyes like rhodamine B and Congo red. The maximum water absorption of synthesized hydrogel was found to be 89 g/g. TEM image revealed the formation of spherical-shape Ag NPs with the particle size of 35 nm. The value of zeta potential was found to be − 23.9 mV. The XRD and SAED patterns agreed with fcc crystalline structure of AgNPs. The synthesized CMC-Ag NPs hydrogel acts as an efficient catalyst for the degradation of rhodamine B and Congo red dyes. The degradation of rhodamine B and Congo red dyes was 14 and 5 times faster when compared with the hydrazine.