Study On Preparation And Application Of Ti/IrCo/RuTiSn Oxide Anode

Electrolytic seawater anti-fouling is the best and most effective technique in preventing cooling water system from marine organisms fouling. The metal oxide anode is crucial element of the technology. The electrocatalytic activity and stability are primary aspects to evaluate the performance of anode. In some sea area, there is lower salinity than the natural sea water, and even is contaminated by Mn²⁺, so there are some defects such as low electrocatalytic activity and short service life in the application of anodes.Based on the above problems, the anodes are prepared by thermal decomposition. The effects of intermediate layer and preparation techics on the performance are discussed. The electrochemical properties of these anodes are studied by chlorine evolution potential and oxygen evolution potential, cyclic voltammetric curves(CV), accelerated life tests and electrochemical impedance spectroscopy(EIS). The anode microcosmic morphology, element composition are charactered by scanning electron microscopy(SEM), electronic probe microanalysis(EPMA) and X-ray diffraction analysis(XRD). An excellent anode are prepared for Electrolyzing seawater, especially for diluent seawater.The effect of intermediate layer on the electrochemical stability of RuTiSn anode is studied firstly. The results show that not only the stability of anode is improved observably, but also it holds high electrocatalytic activity as a result of intermediate layer between Ti substrate and coating. The intermediate layer can block oxygen diffusing to substrate effectively, so its' accelerated life is extended greatly, which is 43 times higher than the anode without intermediate layer. The change of anode before and after degradation is detected by SEM, EPMA and EIS. The deactivation mechanisms are different between anodes without and with intermediate layer. The degradation of former is resulted from the coating flaked off and the insulating TiO₂ grown on Ti substrate, While the latter is mainly resulted from the insulating TiO₂ grown on Ti substrate.The effects on electro-catalytic activity of preparation technics are studied. The results show that the mixed solvent of isopropanol and n-butanol is beneficial to improve the electro-catalytic activity. The superficial cracks are increased and become wider and deeper as the solution concentration increased. As the concentration is 0.4mol/L, the anodic electro-catalytic activity is best. The anodic superficial cracks become more and more visible as the coating times increased. And the coating times should not less than 14 times. The anode prepared at the thermal decomposition temperature of 420℃has better electrocatalytic activity. Its crystal structure of electrode is rutile which is the most stable style.The manganese ion deposited on the anode surface in the form of MnO₂ induced the degradation of the anode dominantly. The current efficiency in natural and diluent seawater and the accelerated life test are measured. The results show that the RuTiSn anode with intermediate layer has higher current efficiency in lower salinity solution and superior property of preventing manganese depositing.