We demonstrate an aqueous solution method for the synthesis of a Ag–TiO₂–reduced graphene oxide (rGO) hybrid nanostructure (NS) in which the Ag and TiO₂ particles are well dispersed on the rGO sheet. The Ag–TiO₂–rGO NS was then used as a template to synthesize Pt–TiO₂–rGO NS. The resulting hybrid NSs were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, UV–vis spectroscopy, Raman spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and catalytic studies. It was found that TiO₂–rGO, Ag–TiO₂–rGO and Pt–TiO₂–rGO NSs all show catalytic activity for the reduction of p-nitrophenol to p-aminophenol by NaBH₄, and that Pt–TiO₂–rGO NS exhibits the highest catalytic activity as well as excellent stability and easy recyclability.

We have demonstrated a one-step and effective electrochemical method to synthesize graphene/MnO₂ nanowall hybrids (GMHs). Graphene oxide (GO) was electrochemically reduced to graphene (GN), accompanied by the simultaneous formation of MnO₂ with a nanowall morphology via cathodic electrochemical deposition. The morphology and structure of the GMHs were systematically characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The resulting GMHs combine the advantages of GN and the nanowall array morphology of MnO₂ in providing a conductive network of amorphous nanocomposite, which shows good electrochemical capacitive behavior. This simple approach should find practical applications in the large-scale production of GMHs.

The synthesis of graphene–semiconductor nanocomposites has attracted increasing attention due to their interesting optoelectronic properties. However the synthesis of such nanocomposites, with decorated particles well dispersed on graphene, is still a great challenge. This work reports a facile, one-step, solvothermal method for the synthesis of graphene–CdS and graphene–ZnS quantum dot nanocomposites directly from graphene oxide, with CdS and ZnS very well dispersed on the graphene nanosheets. Photoluminescence measurements showed that the integration of CdS and ZnS with graphene significantly decreases their photoluminescence. Transient photovoltage studies revealed that the graphene–CdS nanocomposite exhibits a very unexpected strong positive photovoltaic response, while separate samples of graphene and CdS quantum dots (QDs) of a similar size do not show any photovoltaic response.