A facile, one-step solvothermal approach has been utilized for the synthesis of a reduced graphene oxide/Au nanocomposite (RGO/Au) material. Deposition of Au nanoparticles (AuNPs) on the surface of reduced graphene oxide sheets has been realized by a simple reduction of Au precursors and graphite oxide (GO) in ethylene glycol (EG), without using any additional reductants and surfactants. The morphology of the RGO/Au nanocomposite was thoroughly examined by X-ray diffraction (XRD), Fourier transform infrared (FIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The morphology of the RGO/Au nanocomposite was characterized by HRTEM and 20 nm was the average size of the AuNPs obtained. The performance of the RGO/Au nanocomposite has been investigated in the application of the Hg determination at the trace/ultra trace level using differential pulse anodic stripping voltammetry. The composite material was also applied for the determination of p-methoxy phenol (PMP) and, most importantly, it was observed that the material was suitable for the decomposition of PMP by the electrochemical oxidation process. The three sigma detection limits for Hg2+ and PMP were obtained as 0.25 mu gL(-1) and 0.64 mu M, respectively. The applicability of the RGO/Au nanocomposite was further extended to determine Hg soil samples. Chronoamperometric tests were carried out to investigate the performance of modified and unmodified electrodes in the decomposition of PMP by the electrochemical oxidation route. (C) 2015 Elsevier Ltd. All rights reserved.