Preparation Of Titanium-Based Oxides Electrode With Cu-La Doping And Study Of Its Electrooxidation Degradation Of Wastewater

The treatment of wastewater using electrooxidation technology is under globle attention due to such characters as high effieieney, simple operation, easy automation and being benign to environment. In order to prepare high performance, long service life and high stability electrodes, double ion beam sputtering, hydrothermal method and thermal decomposition were used in this paper. Comparisons were made among the electrodes prepared by different methods, including of degradation property, morphology, oxygen evolution potential, fortified life and the production ability of ? OH. Advantages and disadvantages of different methods were analysised. Electrodes were employed to degrade wastewater and the optimum reaction condition was determined. The main study results and conclusions are as follows:(1) The electro-catalytic properties of the electrodes prepared by double ion beam sputtering were increased with sputtering films thickness. The electrode of 100 nm sputtering film thickness displayed a good degradation property and low energy consumption.The removal rate of methylene blue using this electrode was 75.29% in 40 min. However, the optimum electrode prepared by double ion beam sputtering cann’t completely degradate 50 mg/L methylene blue in 40 min. It’s proved that double ion beam sputtering method wasn’t an efficiency manufacture method for electrodes.(2)The electro-catalytic properties of the electrodes prepared by hydrothermal method can be improved by doping. The best doping elements of interlayer were Mn-Ni-Fe with 3% Fe doping amount, while the best doping elements of active layer were Cu-La with 2% Cu and 3% La doping amount. The maximum influence factor was reaction temperature. The second place were reaction time and reaction frequency. The optimum electrode was prepared under the condition of 160 ℃, 48 h and twice times, which can completely degradate 50 mg/L methylene blue in 10 min. Adding TBA duing the reaction can significantly suppress the degradetion of methylene blue, proving that the degradation of methylene blue obeyed ?OH oxidizing reaction mechanism. The degradation of methylene blue with 0 ~ 45 mg/L initial concentration followed the first-order kinetics reaction process. It’s proved that hydrothermal method was a novel high-efficiency manufacture method for electrodes.(3)The electro-catalytic properties of the electrodes prepared by thermal decomposition can be improved by doping. The best doping elements of interlayer were Mn-Ni-Fe with 3% Fe doping amount, while the best doping elements of active layer were Cu-La with 2% Cu and 3% La doping amount. The optimization condition of electro-catalytic reaction was 20 m A/cm2, 0.3 mol/L Na2SO4, p H=5 and 1.0 cm plates distance. The optimum electrode prepared by thermal decomposition was Mn-Ni-Fe/Cu-La, which can completely degradate 50 mg/L methylene blue in 15 min.(4)Electrochemical performance tests showed that electrodes prepared by thermal decomposition had many active sites, high oxygen evolution potential, long fortified life and a good ? OH production ability. Electrodes prepared by hydrothermal method were in the second place. Electrodes prepared by double ion beam sputtering were in the third place.( 5) Mn-Ni-Fe/Cu-La electrode prepared by thermal decomposition was considered as the optimal electrode because of its high degradation property, good stability, long service life and low cost. Amplification effect can suppress the degradating effect to some extent, but the incidence was not in direct proportion to magnification times. Good stability had been Performanced in the dynamic experiments and continuous experiments, showing that the electrode can meet the requirements of long time and high load work. Initial p H can influence the degradating results of real wastewater. COD and ammonia nitrogen can be removed fast by electrooxidation technology. The electrodes showed a good degradating effect to real wastewater.