Cadmium sulphide / Zinc sulphide quantum dot decoration of three-dimensional porous graphene

Graphene, a monolayer of graphite, has appeared as one of the most fascinating materials of today’s Material Science research. The properties of graphene (GR) with high electronic conductivity, extraordinary strength and interesting chemical characteristics make it suitable for many different applications. All these tremendous properties of GR are relevant at the nanoscale, hence, in a view to exploit all these extraordinary properties in macroscopic applications, here, three dimensional (3D) porous structure of reduced graphene oxide (rGO) has been produced by chemical reduction at 90 °C under atmospheric pressure in a solution based process. Quantum dots (QDs) have been widely explored due to their excellent characteristics and the possibilities to tune the optical and electronic properties by controlling their size and structure, as well as their efficient multiple charge-carrier generations. In order to manufacture new nanostructures with low electron-hole recombination, and fast electrontransfer to improve the photovoltaic performance, QDs have been attached homogeneously with rGO sheets in 3D rGO. Alongside with the chemical reduction P H values of GO aqueous suspension were also controlled to produce uniformly QDs decorated 3D rGO. No high pressure or chemical or physical cross-linkers are required in this simple synthesis method to produce QDs decorated 3D rGO with high mechanical strength. Influence of different washing solvent on QDs decoration in 3D rGO has also been analyzed. Decoration of QDs on rGO sheets, their size, crystal structure, and internal structure of QDs decorated 3D rGO were analyzed by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). This 3D architecture of rGO comprised with uniformly QDs decorated GR can be applied in various field because of its combined unique characteristics, for example, multiple charge-carrier generation, electron-hole separation, being light weight, porosity and fast transportation of charge.