Study On The Mechanism And Performance Of Rare Earth Doped SnO₂-coated Electrode

With the rapid development of C hina's industrialization process,emissions of a large number of industrial wastewater make the environmental prob lems become increasingly serious,which poses a great threat to the humanity's survival.Coking waste water is a typical industrial wastewater with of organic pollutants a large number of high concentration,toxic,difficult to degrade,the treatment of these waste water is an urgent problem to be solved.To solve this problem,this paper mainly studied the preparation of modified Sn O₂ electrode,the effect of rare earth doping on electronic structure of Sn O₂,the amount of hydroxyl radicals,electrochemica l properties of Sn O₂ electrode,phenol removal rate and COD removal rate in organic wastewater.And the degradation and degradation mechanism of phenol wastewater by Sn O 2 electrode.The effects of preparation condition,such as doped element?La,Ce,Pr,Nd,Sm,Eu?and doped contents?molar ratio was Sn:Sb:La=100:10:X,X= 0.0,1.0,1.5,2.0,2.5?,on the redox peak,the oxygen evolution potential,the reaction resistance of the Ti/Sb-Sn O₂ electrode and Ti/Sn O₂ electrode were studied with the help of CV curve,EIS,polarization curve,Mott-Schottky curve,hydroxyl radical detection.The effects of doping elements and doping content on the band structure and density of states of Sn O 2 cell were studied by the first principles calculations.The results showed that Lanthanum doped Ti/Sb-Sn O₂ electrode will improve the oxygen evolution potential and active charge electrode,reducing the reaction resistance of the electrode,the electrode negative shift of the flatband potential,active surface area is increased,the carrier concentration further improved,enhanced the catalytic activity of the electrode under the condition of Sn:Sb:La=100:10:1.5.At the same time,the rare earth doped Sn O 2 cell can make the band degenerate,the impurity level,the number of electrons in the conduction band increases,and the conductivity and electrocatalytic activity of the Sn O₂ electrode are improved,especially the rare earth La.The phenol degradation path of Ti/Sb-Sn O₂ electrode under Sn:Sb:La=100:10:1.5 condition was studied by HPLC.The experimental results show that the intermediate products of phenol on Ti/Sb-Sn O₂ electrode in electrocatalytic oxidation are: quinone,maleic acid,resorcinol,catechol,acetic acid and and so on.With the progress of the reaction,the intermediate products gradually decreased,until the acid intermediate product is completely degraded.Finally,the modified Ti/Sb-Sn O₂ electrode was prepared for the treatment of phenolic wastewater.The results show that the electrode voltage of the modified electrode is stable,and the removal rate of COD is improved.The phenol degradation rate of La modified Ti/Sb-Sn O₂ electrode was 90%,and the removal rate was more than four times that of unmodified.It has some advantages in the treatment of organic wastewater.