Composite PbO2-TiO2 materials deposited from colloidal electrolyte: Electrosynthesis, and physicochemical properties

Eiectrodeposition of PbO2 from nitrate solutions in the presence of TiO2 nanoparticles leads to composite PbO2-TiO2 films. The content of the dispersed oxide which is finally occluded into the composite PbO2 film depends on electrodeposition conditions such as pH, the value of the electrodeposition constant current or potential, the amount of added TiO2 and on temperature. It also depends strongly on the presence of anionic additives such as sodium dodecyl sulfate (SDS) whose adsorption decreases the positive charge on the surface of the TiO2 particles. The photo-electrocatalytic activity of the prepared materials has been tested in the oxidation of oxalic acid and benzyl alcohol. Electrodes showed a photoresponse to illumination at lambda > 320 nm confirming literature reports on synergistic effects of illumination in electro-oxidation processes at PbO2-based anodes. We also established that the life service of these electrodes increases by a factor of about 3 with respect to traditional PbO2 anodes. On the other hand, the more striking achievement in the present work with PbO2-TiO2 electrodes is the enhancement of electroactivity in the dark for oxalic acid, benzyl alcohol as well as for O-2 evolution. (C) 2009 Elsevier Ltd. All rights reserved.