Comparative studies on the electrocatalytic properties of modified PbO2 anodes

A set of modified PbO2 anodes doped with the oxides of bismuth and cobalt were prepared by means of electrodeposition in nitrate solutions. Of them, Ti/Bi–PbO2 anode displayed excellent electrocatalytic performance. Cyclic voltammetric experiments were carried out to get a better understanding of the electrocatalytic properties of these anodes. The Ti/Bi–PbO2 anode had the highest overpotential of 1.75 V (vs. SCE) for oxygen evolution. Both XRD patterns and scanning electronic microscopy (SEM) images demonstrated that the incorporation of Bi could diminish the size of the crystal particles. Oxidants such as hydroxyl radical, hydrogen peroxide were determined, and their amount was proportional to the electrocatalyitc activities of modified PbO2 anodes. Electrocatalytic oxidation of o-nitrophenol was conducted by using these anodes as anode and stainless steel sheet as cathode. Ti/Bi–PbO2 anode displayed not only excellent electrocatalytic performance but also low energy consumption. The Ti/Bi–PbO2 anode is a promising anode for the treatment of organic pollutants.