Study On Preparation Technology Of BDD/Ti Composite Membrane Electrode

With the increasing development of social economy and industry, saving resource and environmental protection have been a hot topic. Recently oil extraction increases continuously with rapid development of industry; however wastewater pollution has become the most difficulty due to the oil extraction. Countries in the word try best to adopt many methods in order to reduce oil wastewater damage, which is bad for natural environment and the animal and plant health. There are many wastewater treatment methods, such as physical method, chemical method and electrochemical method. The membrane separation technology is developed in the recent three decades years, which is the new wastewater treatment method. But in dealing with oil wastewater, we encounter a difficult problem—membrane pollution. Membrane pollution will result in lots of problems such as waste of resources and the low efficiency and so on.Based on understanding the reasons of membrane pollution caused in the membrane separation process, we combine the excellent chemical and physical properties and superior electrochemical properties of boron-doped diamond films together, then propose suggest that a new kind of composite material is prepared to solve the membrane pollution problem. The new composite membrane is highly boron-doped diamond film deposited on the porous titanium substruct, which is prepared by hot filament chemical vapor deposition (HFCVD) technology. Porous titanium is a new substract, so the deposition technology needs to be improved and perfected. In this paper, several factors influced the growth of boron-doped diamond films in the deposition process are investigated. The paper mainly focuses on the study of three influced factors, which is strongly influced the diamond growth. While the membrane flux and the cleaning efficiency of different composite membrane samples is measured by simple devices.For the detailed analysis of composite membrane material, surface morphology change, purity and composition substances of boron-doped diamond films are measured by scanning electron microscopy (SEM), Raman spectra analyzer and X-ray diffraction (XRD) device, respectively. The membrane flux is tested by a simple device.Based on the detailed analysis, it is reasonly concluded that mechanical grinded method is more suitable for preprocessing method. Using this mechanical method can provide more diamond nucleation point and nucleation density. The best substract temperature of deposited experiments is 800℃. That is to say, diamond film deposited at this temperature posses clear morphology and the quality is better. It is very complicated that carbon concentration influces the growth of diamond films, but also carbon concentration indirectly influces the formation of titanium carbide. In the low carbon concentration, the growth and quality of diamond films is very good; in the high carbon concentration, the growth and quality of diamond film is very bad, but high carbon concentration can prevent the formation of titanium carbide. The existence of titanium carbide will seriously affect BDD/Ti composite film electrode service life, so we hope the titanium carbide is formed as little as may be. After the comprehensive analysis, a simple and novel deposition method, which is called two-step method, is drawn in order to further improve the deposited technology. This method used in the process of deposition can reduce the formation and obtain high quality diamond film. After the detailed analysis, it is proved that BDD/Ti composite membrane is much excellent than common porous titanium and the cleaning efficiency is different varying quality composite membrane. Finally, we find the excellent preparation technology of BDD/Ti composite membrane electrodes in the actual application. BDD/Ti composite posses many excellent properities such as high efficiency and saving energy, and there will be a good application prospect in the wastewater treatment.