Preparation And Properties Of Natural Dye Sensitized TiO₂-ZnO/RGO Materials

The dye-sensitized solar cell that simulates the principle of photosynthesis in nature is considered to be an ideal substitute for the traditional silicon-based solar cell due to its low cost,simple manufacturing process,diversified shape and color variation with light intensity and stable performance,which has wide market application prospects.In this paper,the problem of small charge-collection-rate and high dye-input-cost in the practical application of dye-sensitized solar cells is studied by preparing semiconductor nanocomposites and using plateau plant dye co-sensitization.Firstly,a high conductivity TiO₂-ZnO/RGO composite was prepared by hydrothermal synthesis.Then,reduced graphene oxide?RGO?was introduced into the TiO₂-ZnO nanocomposite,and the ternary nanocomposite was obtained by hydrothermal method again to improve the utilization of light energy and the charge transfer characteristics which can further increase the photovoltaic efficiency of the battery.The morphological and structural characterization of TiO₂-ZnO/RGO nanocomposites which was obtained by hydrothermal method is collected by using techniques like XRD,TEM,XPS,FT-IR,UV-vis DRS,CV and EIS,etc.Secondly,the dye sensitizers for dye-sensitized solar cells are mostly complexes containing rare metal ruthenium,which are expensive,complicated in the synthesis process,and heavy metal residues.We use high-altitude plants and rely on advanced technology to extract their pigments and apply them to dye-sensitized solar cells.This solves the problems of high dye input cost and heavy metal elements.The main conclusions obtained are as follows:The TiO₂-ZnO/RGO nanocomposites were successfully synthesized by hydrothermal method.TEM images confirmed the presence of TiO₂-ZnO nanoparticles.It was confirmed by FT-IR that the TiO₂-ZnO/RGO nanocomposite was reduced to RGO during hydrothermal process.Furthermore,it has been shown in the UV-vis DR spectrum that the absorption wavelength is increased and the band gap energy is reduced.In addition,the XPS results indicate the presence of C,Ti,Zn and O elements.The CV and EIS results show that the TiO₂-ZnO/RGO nanocomposites have superior electrical conductivity.The lotus and plant leaves were extracted and separated to obtain an anthocyanin dye and a chlorophyll dye with good light absorption properties.Ultraviolet-visible absorption spectroscopy indicated that the blending of the two natural pigments resulted in a full spectrum absorption of the sensitizer between300 and 700 nm.Through electrochemical analysis experiments,when anthocyanin:chlorophyll=2:5,the charge is efficiently injected into the dye and TiO2,and the dye is efficiently regenerated,which greatly increases the photovoltaic parameters of the DSC,and the photoelectric conversion efficiency is increased to 0.22%.