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Abstract: ZnO and graphene composites (ZnO/GR) were prepared by a simple and repeatable thermal evaporation process, and both the reduction of graphene oxide and the loading of ZnO were achieved. The structural and optical properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), atomic force microscope (AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) measurements. In the PL spectra, when the mass ratio of graphene to ZnO increased, a series of fluorescence quenching were found, and a regularly blue shift of the ultraviolet (UV) peak were also found, which might be attributed to the Burstein–Moss effect. [Copyright &y& Elsevier]

Abstract: Well aligned ZnO nails with small heads and rods arrays have been grown on indium tin oxides (ITO) substrates by a simple hydrothermal method without any metal catalyst or additives. The optical properties of the as-grown ZnO microstructures were investigated by room-temperature and temperature-dependent photoluminescence spectra. From the PL spectra measured in the range of 80–300K, the origins of near-band-gap UV lines have been identified in terms of bound exciton complexes and the phonon replicas. We also estimated that the activation energy of the temperature quenching for ZnO nails is higher than that of rods, indicating less nonradiative recombination contributes to the emission process in ZnO nails, which was further testified by the time-resolved PL results. Thus, the relative emission intensity ratio between UV and deep level emission in room-temperature PL spectra for nails is 2.3-times higher than that of rods. [Copyright &y& Elsevier]

Abstract: A series of ZnO and graphene composites (ZnO/GRs) was synthesized by a simple and nontoxic hydrothermal reaction route. The TEM, AFM, FTIR, Raman and current–voltage (I–V) results demonstrated that the ZnO particles were coated by the graphene sheets, confirming the formation of ZnO/GRs composites. During the photocatalytic test, in comparison with ZnO and P25, the ZnO/GRs exhibited enhanced photocatalytic performance for degradation of methylene blue (MB) dye since the graphene sheets could prevent the photoinduced hole–electron pairs of ZnO from recombination by transferring the photoinduced electron to the MB. When the mass ratio of ZnO to graphene was 50:1, the ZnO/GR showed the best photocatalytic performance. Moreover the photocorrosion of ZnO was inhibited to a large extent, which could be attributed to the formation of ZnO and graphene composite. [Copyright &y& Elsevier]