The Preparation And Photoelectric Properties Of Titanium Dioxide Graphene Composites And Nickle-Based Graphene Composites

Dye-sensitized solar cell is a new kind of solar energy conversion device that has attracted great interest globally due to its low cost, easy process of fabrication and excellent efficiency. The counter electrode is one of the most vital components in the dye-sensitized solar cell and can be prepared with various materials and methods. In this thesis, Titanium dioxide/graphene composites and nickle-based graphene composites have been prepared and applied to Dye-sensitized solar cell to investigate their photoelectric properties.Then graphite oxide was scattered by ultrasound together with titanium dioxide, after which graphite oxide was restored into graphene through the reducing method of hydrozine hydrate reducing and UV light. The two samples were tested by scanning electron microscope (SEM), ultraviolet spectrometer (UV), x-ray diffraction (XRD), thermogravimetric analysis (TGA) characterization. The DSSCs are assembled by adopting P25as the photoanode electrode, I-/I3-as the electrolyte electrolytes and samples of which parcel with commercial titanium dioxide (P25) as the counter electrodes. Their electrochemical properties were tested under different lights, such as blue, green, white, UV-light and simulated sunlight. Results of photo-electrochemicial performance show that hydrozine hydrate reducing method has a great advantage over UV reducing method in photo-electrochemicial performance.A phase-adjusted nickel/graphene composite was synthesized by calcinations the mother sample, which showed the Ni(OH)2/graphene after reduced by hydrazine hydrate through hydrothermal method. All the samples have been characterized by scanning electron microscopy, X-ray powder diffraction, transmission electron microscopy, energy-dispersive X-ray spectrometry and thermogravimetric analysis. The obtained Ni-based/graphene composites were used as counter electrode materials of DSSCs to investigate its electrochemical performance. The sample with a phase of nickel oxide has the increased short-circuit current (8.41mA/cm2) comparing with others, which is favorable for the high electrochemical performance in DSSCs.