Preparation Of Rare Earth Oxide-PbO₂-SnO₂/Foam Titanium Electrode

Electro-catalytic oxidation technology is a kind of high efficiency coking wastewater(CW)advanced treatment technology,and the Metal oxide anode also can be called as dimensionally stable anodes(DSA)that are applied to the technology overcome the weakness of traditional electrodes.Taking the SnO2 and PbO2 electrodes having a significant effect on the refractory organic compounds of CW into consideration,it can be an effective way to solve the core problem in the CW advanced treatment with the DSA that are prepared by co-deposition of rare earth in the pulsed electroless plating and Pb combined with Sn in the calcination,and that are featured with high effectiveness and well stability,which will provide a new idea for the preparation of active DSA.The DSA preparation optimal conditions are invested by the analysis of impacts on electrodes properties caused by the Ti-matrix pretreatments,the electroless plating bath composition,pulsed electroless plating parameters and the calcination mechanisms.The impacts of Ti-matrix pretreatments on electroless plating tin are studied;The influence of the plating bath compositions and concentrations,the electroless plating process conditions and the pulse parameters on the coating thickness,binding force,the surface morphology and corrosion resistance of the prepared DSA are also explored;the effects of calcination temperatures and doping amount of rare earth on binding force,the surface morphology,corrosion resistance and the COD removal rate are researched too.The results show that the optimum formula of electroless plating is 12 g/L MS-Sn,60 mL/L MSA,105 g/L thiourea,2 g/L EDTA,40 g/L sodium hypophosphite and 3 g/L hydroquinone.The parameters of pulsed electroless plating are 500 Hz pulse frequency,1.5 A/dm2 current density,30% duty cycle,15 min pulse time,65 ? bath temperature and fast stirring;Stable plating bath and more than 14 ?m of the prepared DSA coating thickness is reached with well corrosion resistance and binding force under the optimum conditions.The prepared DSA have good compactness and catalytic activity when the calcination temperature is 400 ? and the ratio of lead-tin and Ce is 1.5:1:1,which results in the migration of the coking wastewater COD from 114.45 mg/L to 35 mg/L.