| Energy is the fundamental guarantee of human development progress. But the current energy consumption is still based on fossil fuel such as coal, oil and gas.We not only enjoy the energy but also bring the unrecoverable damage to the environment. Now, What we should do are developing and using the new energy whose source is wider, cleaner and more efficient. The task is imminent. Solar energy as a ubiquitous, inexhaustible new energy is a kind of clean resource that we need to develop and utilize urgently.In addition, the environment problem is another major problem that we face. Moreover, with the development of the economy, the adjustment of the contradictions between environmental protection and economic development is becoming more and more difficult. We should consider to the protection of environment when we develop the energy to promote economic development. Solar energy, as a rising star, not only can reduce the usage of the traditional energy but also can decrease the pressure caused by environmental pollution. Solar energy is the clean resource that we should develop and utilize.Semiconductor photoelectric functional materials are one of ligaments of realizing the photoelectric conversion. At present, photoelectric functional material have been developed from bulk material to thin layer and micro-nano material of quantum dot size. When the size of the semiconductor material reduces to the nanometer level, its band structure divides into discrete energy levels and band gap also increases with the decrease of the particle size. Therefore, we can make the light absorption of material to match the energy of the solar spectrum as far as possible. Which can be achieved by adjusting the particle size.Ti O2 and Zn O are two kind of common nanometer semiconductor photoelectric functional materials. They have good stability and photoelectric conversion performance. Researchers are interested in studying them. However, there are great obstacles when we use these conventional materials, such as wide band gap and low quantum efficiency and so on. So we must synthesize the narrow band gap semiconductor materials to sensitize these materials in order to that we make full use of these good conventional materials and raise the efficiency of photoelectric conversion. Graphene was found by Andre Geim and Konstantin Novoselov, which the thinnest nanomaterial in the world. It’s resistivity is very low which can lead to the fact that the electron transfer rate is specially fast. It suits for application in the photoelectric field. Graphene oxide(GO) is semiconductor material. It has the steady and the narrow band gap and the quantum size effect which will be found when the size reduces very small. So we will combine graphene quantum dots(GOQDs) and Ti O2. Research on the process of the separation of electrons and the transport mechanism in the material will help us to design the more excellent photoelectric functional materials with good performance. And then we can promote the effective utilization of solar energy.We need to use some characterization methods and test methods to research and develop photoelectric functional material with better excellent performance. The morphology and size can be characterized by the transmission electron microscopy(TEM) and X-ray(XRD). The process of the separation of electrons and the transport mechanism in the material can be analyzed by the change of the photocurrent. The mechanism of photocatalytic degradation of pollutants can be infered by photoactivate experiments.For above reasons, the main contents of this paper are as follows:(1) The GOQDs was synthesize by the method of nitric acid oxidation and its structure is characterizated by infrared spectrum, X-ray diffraction(XRD), Zeta potential, UV-Vis absorption spectroscopy and transmission electron microscopy(SEM). The UV-Vis absorption spectrum illustrates that the GOQDs has certain response to visible light and set the stage for subsequent experiments.(2) The Ti O2 porous microsphere was obtained by a with mild hydrothermal method and combined it with GOQDs. Photocatalytic degradation of rhodamine B and photocurrent test illustrate that the complex is responsive to visible light. Using the method of the linear scanning and the Mott-Schottky illustrate the photoproduction charge, transfer mechanism and the principle of photocatalytic degradation of rhodamine B,which illustrate that the composite material has potential application in photocatalytic degradation of pollutants.(3) The strontium titanate porous microspheres were also prepared using basal material of Ti O2 and combine it with GOQDs. Then it was used for photocatalytic and photocurrent experiments. At the same time, the mechanism of electron-holes transfer was explained. |
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