Green synthesis of Ag NPs on magnetic polyallylamine decorated g-CN by Heracleum persicum extract: efficient catalyst for reduction of dyes.

Silver nanoparticles were immobilized on magnetic polyallylamine (PAA) decorated g-CN by using Heracleum persicum extract as a biological reducing and stabilizing agent. The resulting nanocomposite, FeO-g-CN-TCT-PAA-Ag, was then characterized using BET, VSM, XRD, TGA, FTIR, TEM, EDS and ICP. The catalytic performance of the synthesized nanocatalyst was considered in the reduction of rhodamine B, and methyl orange in the presence of sodium borohydride in the aqueous medium at room temperature. The results showed that FeO-g-CN-TCT-PAA-Ag nanocomposite could promote both reduction reactions efficiently in very short reaction times (70-100 s). In addition, FeO-g-CN-TCT-PAA-Ag could be magnetically recovered and recycled for several cycles with no significant decrease in its catalytic performance. Using the experimental results, the rate constant, enthalpy, and entropy of the reduction reactions of both dyes were estimated.