Electrospinning Preparation Of One-dimensional Titanium Dioxide And Its Application In Dye-sensitized Solar Cells

With the rapid development of human society,science and technology and social productivity,the cost of petroleum products lower is reducing the demand for energy is increasing.However,the "energy crisis" and the environmental problems brought by fossil fuels have also come into being.People are paying more attention on it.It is imperative to expand renewable and environmentally friendly new energy sources.Dye-sensitized solar cell(DSSC)has attracted many researchers due to its low cost,simple preparation process,relatively low production cost,environment-friendly,and long life.It is very important to solve the global energy crisis.Photoanode is playing an important role in DSSC.As the preferred photoanode semiconductor material for DSSC,Titanium dioxide(TiO2)has unique features such as sunlight capture,dye adsorption,electron injection and collection,and electronic recombination.So it has a great influence on the power conversion efficiency of DSSC.Therefore,the size of the specific surface area of TiO2,its response range to light,and the electron and hole recombination rate all directly affect the efficiency of DSSC.Porous thin-film electrodes are one of the important factors affecting the performance and stability of DSSC.At present,one-dimensional(1D)nano TiO2 is a structural material with excellent photoelectric properties,which is beneficial to improve the photoelectric properties of porous thin films.This paper aims at designing a highly efficient DSSC porous thin film electrode and improving the microstructure of the porous thin film by introducing 1D nanostructured TiO2.It not only establishes a pathway for rapid electron transport and a light scattering center,but also develops a variety of composite porous thin films for using in DSSC.Electrospinning is a simple and effective method for the preparation of 1D nanomaterials.In this paper,DSSC photoanode materials were prepared by electrospinning,and the photoelectric properties of the assembled DSSC were studied.(1)1D TiO2 nanofibers were prepared by electrospinning technology.The crystallinity,specific surface area,pore size distribution,surface elements,structure and other physical properties of 1D TiO2 nanofibers were characterized and analyzed.The composite photoanode of TiO2 nanoparticles/nanofibers was prepared,and the influence of film thickness on photoelectric properties of different electrospinning films was explored.According to the electrochemical properties,the power conversion efficiency was 6.5%when the electrospinning time of the fiber film was 15 min.The main reason can be attributed to:TiO2 nanoparticles can be used as both a paste layer and a hole blocker,effectively reducing the interfacial resistance as a binder;1D TiO2 provides a channel for electrons.(2)In DSSC,in order to reduce the recombination of electrons and holes on the interface,nanoparticle/nanofiber composite photoanodes were modified.The composite photoanode on the prepared surface was scratch coated with a zirconium oxide(ZrO2)paste,and ZrO2 as a barrier layer was able to reduce the recombination of electron-holes between TiO2/dye-electrolyte.XRD,FESEM-mapping,HRTEM,XPS,and other related physical characterizations have proved the existence of ZrO2 and its distribution in photoanode.Electrochemical characterization have proved the improvement of power conversion efficiency is originate from the reduction of the recombination of electrons and holes.(3)In DSSC,noble metal modification plays an important role in solving the light absorption of titanium dioxide films and reducing the recombination of electrons and holes.In the preparation of nanoparticle/nanofiber composite photoanode,immersed in O.Olmol/L AgNO3 solution,silver was deposited by the method of ultraviolet reduction silver plating,and different contents of silver were obtained according to different reduction time.Using FESEM-mapping,TEM,XPS and other characterization to study the distribution of Ag in the photoanode.And electrochemical characterization,the results show that the power conversion efficiency was best when the reduction time was 45 s.