Insights into the catalytic reduction of organic dyes and antibacterial activity of graphene oxide supported mono and bimetallic nanocomposites

Graphene oxide (GO) supported mono (GO/Ru, GO/Ag and GO/Pd) and bimetallic (GO/Ru–Ag and GO/Ru–Pd) nanocomposites (NCs) were prepared via a simple chemical reduction method. The newly designed GO-supported mono and bimetallic NCs were characterized using various techniques, such as Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX) and high resolution transmission electron microscopy (HR-TEM). Furthermore, the GO-supported mono and bimetallic NCs were utilized for the reduction of two organic dyes, crystal violet (CV) and malachite green (MG), using NaBH4 in an aqueous medium at 25 °C. The catalytic reaction followed pseudo-first-order reaction kinetics, as monitored using UV-visible spectroscopy. In addition to this, the antibacterial activity of these prepared mono and bimetallic NCs was studied against two Gram (+ve), Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis), and two Gram (−ve) bacteria, Salmonella typhi (S. typhi) and Escherichia coli (E. coli). The bimetallic NCs exhibited excellent catalytic and antibacterial activity as compared to the monometallic NCs.