The Composition and Physicochemical Properties of PbO2–TiO2 Composite Materials Deposited from Colloid Electrolytes

Resumo

The effect of the deposition conditions from colloid electrolytes on the chemical and phase composition, texture and electrocatalytic activity of PbO₂–TiO₂ composite materials was studied. The composition of the composites depends on the electrolysis regimes, the charge of the dispersed phase particles and the electrode, as well as the precipitation rate of lead dioxide, and the concentration of the components in the solution. By varying the electrolysis regimes and the composition of the electrolyte, composites with a TiO₂ content of up to 27 wt % can be obtained. The phase composition and texture of the resulting composites are determined by the electrolysis regimes and the composition of the electrolytes used. In addition, the presence of TiO₂ particles in the electrolyte leads, as a rule, to a decrease in crystal size and an increase in the content of α-phase of lead dioxide in the precipitate. Introduction of valve metal oxide particles into the lead dioxide materials generally results in an increase in OER overvoltage and in the rate of p-nitroaniline oxidative degradation due increasing the number of oxygen-bound particles firmly bound to the electrode surface and the parallel flow of photocatalytic processes at TiO₂ centers, providing additional quantity of oxygen-containing oxidants of radical and peroxide nature. The use of composite materials as an active and transition layer of low-wearing anodes makes it possible to obtain electrodes with a long service lifetime.