Preparation Of Porous Titanium Dioxide Film Electrode And Its Applications On Organic Electro-synthesis

Titanium dioxide is a good semiconductor functional material and widely used in many fields,such as organic synthesis and degradation,photoelectrocatalysis,solar cells and other areas.The characteristics of the functional material depend on its microstructure.Because of its larger specific surface area and more active sites,the efficiency of titanium dioxide nanomaterials in organic synthesis is greatly increased,as well as the photoelectric conversion efficiency in solar cell,all of this are suit for the current social development and industrial production.At present,there are more and more studies on the titanium dioxide nanomaterials,which promise it an immeasurable prospect.（1）Effect factors of porous Ti02 electrode by anodizationThere are many methods about the preparation of titania nanotubes electrodes have been proposed,which are mainly divided into electrochemical methods and non-electrochemical methods.Anodic oxidation is one of the most frequently used methods among all of the electrochemical methods.Compared with other methods of preparation,anodic oxidation has many advantages,for example,the simple operation,mild conditions.And then nanotube arrays prepared by anodic oxidation have the characteristics of self-organization and high orderliness,which makes it highly fancied.In this study the effect factors of fabrication porous Ti02 electrode including electrolyte,work voltage,reaction time and temperature were specifically analyzed and discussed and the preparing conditions of TiO₂ nanotube electrode were further optimized.Electrolyte is made up with glycerol 50mL and distilled water 50mL,2.84g Na2SO4 and 0.55g NaF,the voltage 20V,the electrolysis time 1.5h,and the electrolysis temperature 20℃.The distance between anode and cathode is 3cm.（2）Electrocatalytic performance of porous TiO₂ electrodeThe electrocatalytic performance of the porous TiO₂ was tested by cyclic voltammetry in lmol/L oxalic acid solution compared with a blank electrolyte of 1mol/L H2SO4.The test results showed that titania nanotubes electrode can provide a strong electro-catalytic properties.It is stronger than the titania film electrode can provide.The reduction process of oxalic acid was rapid and irreversible.It gives a verdict of Ti02 nanotubes electrodes in the field of organic synthesis having a very broad application prospects.（3）The electrolysis performance of porous TiO₂ electrodeGalvanostatic electrolysis experiments of oxalic acid were carried out with porous TiO₂ electrode.The results showed that in the undivided cell TiO₂ nanotube electrode as the cathode,DSA as the anode,under the conditions of temperature 20℃,current density 300 A/m² and electrolysis time 4h,different concentration and yield of glyoxylic acid were obtained with different concentration of oxalic acid.The highest yield of glyoxylic aicd（72.1%）was obtained in the 0.3 mol/L oxalic acid.The current efficiency increased with the increase of the concentration of oxalic acid and the oxalic acid conversion rate decreased with the increase of the concentration of oxalic acid.