Efficient and easily retrievable green modified carboxymethyl cellulose coated A. indica stem bark encapsulated metal nanoparticles towards the reduction of o-nitrophenol and azo dyes

Abstract

A new type of economically feasible and environmental-friendly Azadirachta indica stem bark (AIB)/sulfated carboxymethyl cellulose (AIB/S-CMC) based bio-composite catalysts decorated with efficient zero-valent metal nanoparticles were fabricated through an easy and fast chemical approach. First of all, sodium salt of carboxymethyl cellulose (CMC) was modified into sulfated-CMC (S-CMC) by a non-toxic sulfating agent followed by dip coating on AIB pellets. The AIB/S-CMC bio-composites decorated with M0 = Ag, Co, Cu, Ni, Ag-Co, and Cu-Co(M0-AIB/S-CMC) were analyzed by different techniques such as FE-SEM, EDAX, UV–Vis, XRD, and FTIR, which confirmed that the metal nanoprticles were successfully synthesized and well dispersed on the surface of fabricated bio-composite catalysts. The M0-AIB/S-CMC bio-composites were then subjected to extensive evaluation and investigation of its potential ability as efficient catalyst for reduction of 2-nitrophenol (2-NP) and toxic dyes. The results demonstrated that Co-AIB/S-CMC bio-composite catalyst exhibits good stabilities and catalytic activities for the reduction of 2-NP and azo dyes (acid red and methyl orange). Despite of having a good catalytic ability, Co-AIB/S-CMC bio-composite catalysts could be easily recoverable from aqueous media after completion of the reaction simply by pulling the pellets from the reaction matrix.