The Synthesis of Structural Controllable Titanium Dioxide Nanorods Array and Its Electrochemical Performance
|School||East China University of Science and Technology|
|Course||Materials Science and Engineering|
|Keywords||Titanium dioxide hydrothermal synthesis solvothermal synthesis nanorods array dye-sensitized solar cells|
The titanium dioxide nanometer material is widely applied in many fields due to its outstanding performance. The controllable synthesis and application research is the hot spots in nanotechnology area in recent years. This thesis focused on the one-dimensional TiO2 nanorods array and it was prepared in both strong acid and weak acid conditions. The morphology, structure and electrochemical performance of the TiO2 thin film were studied separately. The mechanism of the growing and evolution of the TiO2 thin film in the weak acid condition is also discussed.1. The rutile TiO2 nanorods array with homogeneous structure was prepared via hydrothermal method with the hydrochloric acid and H2O as its solvent and tetrabutyl titanate as its precursor. The diameter, length and density of the nanorods array is relevant with its reaction condition such as time, temperature, precursor concentration, addition agent and HCl volume. The DSSC with the anode reacting for 5h showed a light-to-electricity conversion efficiency of 1.2%. A compact layer was prepared on the surface of the FTO glass by a home-made spray pyrolysis equipment. The compact layer on the FTO glass promoted the growth of the TiO2 array. The conversion efficiency of the DSSC with the compact layer anode on the same reaction condition for 5h had a rise of 17%, reach 1.4%.2. The rutile TiO2 nanorods array thin film was prepared via solvothermal method with ethanol and acetic acid as its solvent, TiCl4 as its precursor. The as prepared thin film had a high transparency and double-decker structure, the forming process and mechanism of the thin film is a dynamic balance and energy minimization evolvement. The DSSC made of this film had a conversion efficiency of 3.9% and it reached 5.3% and 7.3% after being made into composite structure cells with large particle scattering layer and P25 plus scattering layer separately. Increasing the percentage of the acetic acid in the solvent could obtain TiO2 thin film with both rutile and anatase phase, and its structure turned into quasi-1D aggregates. The DSSC made of this film had a conversion efficiency of 4.2%, and can reach 5.1% after cyclic growth for 3 times. Further increase the percentage of acetic acid in the solvent could obtain pure anatase TiO2 film and the as assembled DSSC can get a conversion efficiency of 1.7%.