Green synthesis, characterization and catalytic application of silver‐graphene oxide nanocomposite for the reduction of nitrophenols and benzaldehyde

BACKGROUND The industrial effluents contain toxic, persistent, and bioaccumulative nitrophenols and aromatic aldehydes, which pose serious environmental and health hazards. In the present study, a silver‐graphene oxide (Ag‐GO) nanocomposite was synthesized using Berberis lycium plant extract as a green reducing and stabilizing agent. The Ag‐GO nanocomposite was characterized using various techniques that revealed the crystalline nature of silver nanoparticles that were well dispersed on the GO surface with strong interaction. The Ag‐GO nanocomposite was applied as catalyst for the reduction of 2,4,6‐trinitrophenol, 2‐nitrophenol, 4‐nitrophenol, and benzaldehyde in aqueous medium using NaBH 4 as a reducing agent. RESULTS The UV–Visible spectroscopy was used to monitor the progressive decrease in the absorption peaks of nitrophenols and benzaldehyde. The Ag‐GO nanocomposite exhibited high catalytic efficiency in the reduction reactions, which were carried out at 15 °C. The reactions followed pseudo‐first‐order model with high correlation coefficient ( R 2 ) values (0.9806–0.9953) whereas the rate constants ( k ) were found to be in the range of 1.6 × 10 −4 to 4.0 × 10 −4 s −1 . CONCLUSION The catalytic activity of Ag‐GO nanocomposite was attributed to its high adsorption affinity for substrate molecules as well as increased electron transfer due to synergistic effect of Ag nanoparticles and graphene oxide.