UV irradiation synthesis of an Au-graphene nanocomposite with enhanced electrochemical sensing properties

A facile and environmentally friendly strategy using UV irradiation has been successfully developed for the preparation of an Au-reduced graphene oxide (Au-RGO) nanocomposite. The as-prepared nanocomposite was analysed and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the simultaneous reduction of graphene oxide and formation of Au nanoparticles were achieved. The obtained Au nanoparticles with an average diameter of 25.7 nm were uniformly dispersed on graphene sheets. The introduction of Au nanoparticles has efficiently maximized the electroactive surface area of catalysts and the conductivity of the Au-RGO nanocomposite. The graphene sheets not only provided the nucleation sites but also prevented the Au nanoparticles from agglomerating. Moreover, in order to illuminate the advantages of the Au-RGO nanocomposite, its electrochemical sensing performance toward TNT as an example has been further investigated by cyclic voltammetry (CV) and linear scan voltammetry (LSV). The results confirmed that the Au-RGO nanocomposite exhibited much better electrocatalytic activity toward TNT than RGO and holds great promise for developing as an electrochemical sensor.