Immobilization of Gold-Aryl Nanoparticles Over Graphene Oxide Platforms: Experimental and Molecular Dynamics Calculations Study

Graphene oxide (GO) was decorated with gold-aryl (Au-C) nanoparticles of AuNPs-COOH by sodium borohydride reduction of aryldiazonium tetrachloroaurate(III) salt at room temperature in aqueous solutions. Morphology of AuNPs-COOH/GO nanocomposite (NC) was probed using atomic force microscopy (AFM) and transmission electron microscopy (TEM), showing NC surface roughness and wrinkling. X-ray photoelectron spectroscopy (XPS) results suggest the clear reductive reaction of tetrachloroaurate anion into metallic gold in AuNPs-COOH/GO along with detailed interpretations of the nature of the functional groups. Brunauer-Emmett-Teller measurements supported GO anchoring by AuNPs modified with COOH; surface area dropped significantly. Molecular dynamics calculations endowed support of favorable wrinkling at the edges and carboxyl intercalation to GO surface of types pi-pi, hydrogen bonding, and hydrophobic interactions. Solvent accessible surface area calculations of GO showed a decrease in total surface area.

Automated summary

In this study, graphene oxide was decorated with gold-aryl nanoparticles by reducing aryldiazonium tetrachloroaurate(III) salt with sodium borohydride at room temperature. The resulting gold-aryl/graphene oxide nanocomposite exhibited a rough and wrinkled surface. X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller measurements confirmed the successful anchoring of gold nanoparticles on graphene oxide and a decrease in surface area of the nanocomposite.