Designing versatile heterogeneous catalysts based on Ag and Au nanoparticles decorated on chitosan functionalized graphene oxide

Abstract

Herein we report the covalent grafting of chitosan on graphene oxide (GO) followed by a simple approach for anchoring silver (AgNPs) and gold (AuNPs) nanoparticles onto a chitosan grafted graphene oxide surface by a NaBH4 reduction method. Catalytic activity of prepared heterogeneous GO grafted chitosan stabilized silver and gold nanocatalysts (GO-Chit-Ag/AuNPs) was explored for the reduction of aromatic nitroarenes and degradation of hazardous azo dyes in the presence of NaBH4. Both catalysts were found to exhibit excellent catalytic activity towards the reduction of aromatic nitroarenes and azo dyes degradation. Furthermore, the nanocatalysts were found to be selective towards the reduction of nitro groups in halonitroarenes without any dehalogenation under mild conditions.

Synthesis of silver nanoparticles using bacterial exopolysaccharide and its application for degradation of azo-dyes

“…A 3 mL of 10 −5  M aqueous solutions of MO and CR in a quartz cuvette were taken and 5 mg of EPS-AgNPs solution was added separately. To this reaction mixture, 50 mL of 0.1 M NaBH 4 was added, and the decreasing absorption maximums of the azo-dyes were recorded [22].…”

Modified Nanocarbons for Catalysis

“…The same chitosan modified GO support was also used for the immobilization of Ag and Au NPs and the obtained materials 116 b and 116 c , respectively, were used as catalysts in the reduction of nitroarenes into the corresponding anilines (Scheme ) . Catalyst 116 b was recycled for ten cycles with a slight loss of activity starting from the 6 th catalytic run.…”

Eco-friendly synthesis and catalytic application of chitosan/gold/carbon nanotube nanocomposite films

“…Some reduced catalytic activity was retained since the Au-NPs were still present. 36 This is one of the primary reasons for employing a support. 6.…”

“…24 To overcome this, CNTs have been functionalized using a number of chemical methods and also by irradiation techniques. 36 Thus the overall process is environmentally hazardous and there is a growing need to replace it with cleaner, non-toxic, reusable and eco-friendly methods. It is very effective in creating functional groups on the surface of the CNTs.…”