Investigation Of The Preparation Process Of The ZnO/3D-Graphene Nanocomposites

The preparation of nanocomposites composed of two or more components with desirable performance are currently one of the most popular research topics, due to the synergic effect between the components. Graphene, a flat monolayer nanosheet of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, has attracted intense interest in recent years owing to its intriguing properties, such as high electronic conductivity, excellent chemical stability and high specific surface area. Its unique 2D structure and π conjugated system provide a suitable platform for the growth and stability of inorganic nanoparticles. Among the inorganic nanoparticles, ZnO is an attractive semiconductor material due to its exceptional electrical, optical and piezoelectric properties. In this study, we focus on the preparation of ZnO nanoparticles decorated three-dimensional (3D) porous graphene electrodes.First,3D-graphene structures were prepared from graphene oxide (GO) gel through a facile process that comprised of spin coating, freeze drying, and thermal reduction. The morphology and structures can be tuned by changing the preparing conditions. The 3D graphene films generally have low density and highly porous structures, with pore size being several tens of micrometers, which enable easy access and diffusion of ions and molecules throughout the highly porous structures.Secondly, the 3D graphene structures were decorated with ZnO through electrochemical deposition. The influence factors such as deposition potential and deposition time were optimized to obtain a proper deposition quantity and a proper size of the ZnO particles. The structure and distribution of ZnO nanoparticles on the RGO sheets were characterized by using X-ray diffraction (XRD), Raman spectra (Raman) and scanning electron microscope (SEM). Photoluminescence (PL) spectra indicated that the PL emission of ZnO in the RGO/ZnO composite films was quenched by RGO, implying the possible application of the ZnO/RGO nanocomposites photoelectronics.