Modified lead dioxide for organic wastewater treatment: Physicochemical properties and electrocatalytic activity

An investigation is reported on lead dioxide electrodeposition from methanesulfonate electrolytes, those additionally containing Ni 2+ ions. It has been shown that lead dioxide electrodes micromodified by nickel that have different physico-chemical properties vs. nonmodified PbO 2 -anodes are formed during the deposition. Electrocatalytical reactivity of electrodes involved in respect to both the oxygen evolution, as well as to the electrooxidation of 2,4- dichlorophenoxyacetic acid was investigated. P rocesses of electrochemical oxidation of 2,4-D on various materials occur qualitatively the same and differ only in the rate. It was revealed that Ni-PbO 2 -anode possesses the highest electrocatalytic activity, the destruction rate of 2,4-D on it increases in 1.5 times in comparison with nonmodified lead dioxide.The COD of a 0.4 mM solution of 2,4-D, determined by the dichromate method, is 90.0 mg dm -3 which is 94% of the theoretical.