Photoactive Graphene-Synthesis And Photoelectric Property Study

In this thesis, photoactive graphene based nanoscale complexes were designed and prepared, and their photonics, electronics and photoelectric response performance were studied. The main graphene composites materials under investigation include organic small molecules covalently functionalized photoactive graphene composites; organic donor (acceptor) non-covalently functionalized graphene composite films, and heteroatom doped graphene as well as graphene quantum dots. The obtained photoactive graphene based nanocomposites were characterized to explore their potential applications in the fields like solar cells and gas sensors. Meanwhile, graphene analogues (such as MoS2) based hybrid films were also prepared and their photoelectric response performance were investigated. Our results may help to design novel graphene based solar cells and gas sensors devices and catalyze the approaching of low-cost manufacturing.The main results in this thesis are listed as follows:1. By using "click" chemistry, two novel photoactive graphene materials have been prepared at the first time. Firstly, graphene modified by phenylacetylene moieties provide a facile platform for attaching various photoactive functional molecules via "click" chemistry. Next, various characterization approaches have been employed to make sure that photoactive molecules were covalently functionalized onto graphene surface through "click" chemistry. Furthermore, photoelectric response performance measurement results shown that photoactive graphene exhibited dramatically increased photocurrent generation as compared with the unmodified graphene.2. The Langmuir-Blodgett (L-B) self-assembly technology was employed to prepare1to3layers r-GO films. The relationships between graphene film layer number (thickness) and electronic property, as well as the gas sensor performance for common gases (such as NH3, NO2) were systemically investigated. Furthermore, graphene films were non-covalently functionalized with TTF derivative and TCNQ, which are the commonly used organic electron donor and acceptor molecules, respectively. The gas sensor properties of these graphene films were investigated.3. We reported a facile approach to synthesis heteroatom doped graphene quantum dots (GQDs), and further achieved their application in solar cells. On the basis of preliminary investigated the structure, photonics and electronics properties of GQDs, layered GQDs/inorganic semiconductor quantum dots (QDs) hybrid films were prepared for photovoltaic properties research. Furthermore, TiO2/GQDs nanotube arrays based solid state photovoltaic devices were prepared and their performances were studied.4. Layered graphene analogues (GAs) hybrid films were designed and prepared, their photovoltaic properties were also investigated. Firstly, a mixed-solvent strategy was used to exfoliate graphene analogues dispersion liquid. Secondly, the photoelectrochemical cells consisting work electrode with layered GAs/QDs hybrid films were prepared by using electro-deposition and successive ionic layer adsorption and reaction (SILAR) approaches, and their photoelectric response performances were investigated.