Preparation And Performance Test Of The The Oxygen Evolution Semi-conductor Electrode

In the electrolytic recovery of heavy metals in the chloride system, the high concentra-tion of Cl-1in the electrolyte solution will be oxidized to chlorine gas by the anode. The gen-erated chlorine would change the nature of the electrolyte, effect electrolysis metal qualityand cause serious pollution of the environment. Huge amounts of chlorine must be collectedand absorbed by alkali, in order to eliminate chlorine contamination to the external environ-ment, which in return to raise the cost of production. It is a feasible and effective way tochange the anode material evolution of oxygen and chlorine evolution performance to preventthe generated of chlorine on the anode.The lower overpotential electrode material have a higher electrocatalytic activity in con-dition of different electrode and same current density. Oxide surface oxygen evolution pro-cess will occur only when the anode potential is higher than the standard electrode potentialof the upset oxide/higher oxides.The lower the standard electrode potential of the suboxide/high oxides is，the greater the oxygen evolution catalyst activity will be. The Ti/MnO₂electrode belongs to the oxygen evolution DSA electrodes, having a very high catalytic activ-ity to oxygen evolution reaction, and a good corrosion resistance in lots of media. It is hard todissolve during the electrowinning process and will not pollute the electrodeposition products.Mn, as non-precious metals, the price is low.These features do not only satisfy the the purposeof nhibiting chlorine generated in the chloride system Deposition of non-ferrous metals，butalso to ensure the purity of the product of electrowinning.At the same time it is also condu-cive to the promotion and application of the industrialization of the electrode due to the lowproduction cost.It is an ideal electrode material of titanium coating in the nature of the oxygenevolution.Obtained by experiment, the best conditions for electroplating MnO₂on Titanium sub-strates are as follows:the temperature of Titanium plate cathode is85°C，a current density of50A/m2in the150g/L MnSO₄and50g/L H₂SO₄mixed solution, both sides electroplated atthe same time for45minuntes. Compared with the performance of graphite elctrode, cot-ton-like graphite electrode,fiber the cavernous graphite electrode,and titanium coated withruthenium electrode,Ti/MnO₂anode‵s advantage is a higher electro-catalytic activity in theoxygen evolution reaction and lower oxygen evolution overpotential，while a lot of short-comings, such as resistors, conductive poor, short life,and so on.In order to improve the performance of an electrode, we selected two intermediate coat-ings to make the Ti/SnO₂+MnO_x+Ru_Ox/MnO₂coated electrode and Ti/SnO₂+Sb₂O₄/MnO₂coated electrode. Through the experimental comparison, Ti/SnO₂+Sb₂O₄/MnO₂ coated electrode has higher conductivity, lower resistance of the electrode and oxygen evo-lution overpotential,and longer electrode life.It is a good performanced oxygen evolutionelectrod.It can effectively reduce the generated chlorine gas, when used in the electrolytic re-covery of precious metal process from the chloride system.