Cactus-like and honeycomb-like zinc selenide microspheres on graphene oxide sheets with excellent optical properties

Novel cactus-like and honeycomb-like ZnSe microspheres have been successfully grown on graphene oxide sheets by hydrothermal method at 190°C for 24h. The morphologies, structures, chemical compositions and optical properties of the as-grown ZnSe microspheres were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), X-ray energy dispersive spectrometer (EDS) and Raman spectra. It was found that the concentration of EDTA was important for the formation of morphologies of ZnSe microspheres. The cactus-like ZnSe microspheres were formed when the concentration of EDTA was 0.3M. With increasing the concentration of EDTA to 0.45M, honeycomb-like ZnSe microspheres were formed. The results of XRD revealed that the as-grown ZnSe microspheres have cubic zinc blende structure. Room temperature photoluminescence (PL) showed that the samples emit blue-green light under ultraviolet light. The results of Raman spectra, XRD and SEM showed that the ZnSe microspheres were grown on graphene oxide sheets. The formation mechanism of ZnSe microspheres grown on graphene oxide sheets was also discussed.