Preparation,Characterization And Electrocatalytic Performance Of Nano-TiO₂/CNT Film And Chiral Amino Acid Modified Composite Film Electrode

The paper is composed of the following three parts: First, Electrochemical impedance spectra ,cyclic osteryoung square wave voltammogram and cyclic voltammogram of nano-TiO₂ Electrode. The electrochemical behavior of Ti/nano-TiO₂ film electrode was investigated by Electrochemical Impedance Spectra(EIS),Cyclic Voltammogram(CV)and Cyclic Square Wave Voltammogram(CSWV) in two different solutions, and relevant equivalent circuit and electrochemical kinetic parameters were presented. The results indicate that there are two pairs of well-defined redox peaks for Ti/nano-TiO₂ film in correspondence with TiO₂/Ti₂O₃ and TiO₂/Ti(OH)₃ two heterogeneous redox reversible electrode process; and applied electric potential and the quality of electrolyte have prominent influence on the interface structure and superficial electrochemical reaction speeds, electrode impedance consisted of film resistance Rf,electrochemical polarization impedance Rct and Warburg impedance Zw in the potential range of film reaction, The Rf are 125Ω·cm² and 7.45×10³Î©Â·cm² respectively in 1 mol/L H₂SO₄ and 0.5mol/L HAc-NaAc buffer electrolyte included ethanol, and there were dispersion effect due to the roughness and inhomogeneity of nano-TiO₂ film surface. Second, Electrochemical performance on nano-TiO₂/CNT composite film modified electrode. In terms of Electrochemical Impedance Spectra(EIS),Cyclic Voltammetry,Chronocoulometry,Impedance-potential and TEM, We researched and compared the electrochemical characteristic difference between composite nano-TiO₂/C-nanotube (nano-TiO₂/CNT) modified electrode and pure nano-TiO₂ modified electrode, a great deal of carbon nanotubes are in existence, which can block the reunite effect of nano-TiO₂ particle. The unique atomic structure of carbon nanotube can accelerate electron transfer in electrochemical reaction and bring proper catalytical response. Compare to pure nano-TiO₂ modified electrode, the current values of the second redox peaks of nano-TiO₂/CNT modified electrode are about twice higher than pure nano-TiO₂ modified electrode's, and quantity of electric charge increases greatly at the same time. and it is further proved by the heterogeneous electrocatalytic reduction of maleic acid etc. Third, Studies on amino acid chiral modified electrode. L-Cysteine-nano-TiO₂/CNT(L-Cys-nano-TiO₂/CNT) chiral modified electrode was prepared by self assemble and several methods such as FTIR spectrum, Scanning Electron Microscopy, Impedance,Cyclic Voltammogram were used to investigate the electrochemical properties on the surface,and we electrodeposited Ag on the nano-TiO₂/CNT surface with electrochemical scan, and got L-Cys-Ag–nano-TiO₂/CNT chiral modified electrode by self assemble. There were a pair of redox peaks of Ag-nano-TiO₂/CNT electrode in 1mol/L H₂SO₄, L-Cys-Ag–nano -TiO₂/CNT chiral electrode had proper electrocatalytic activity to hypnone reduction,and it was rather stability.