Electrochemical Method for Producing a TiO2 Film with Photocatalytic Properties

Abstract

The purpose of this work is to study the production process of titanium dioxide during anode polarization in sulfuric acid and hydrochloric acid solutions. The studies were carried out by recording cyclic voltammogram and by measuring the titanium oxidation current with a change in the voltage between the electrodes. It has been established that with a change in the concentration of sulfuric acid in the range of 50–250 g/l and the voltage between the electrodes in the range of 0–25 V, the magnitude of the titanium oxidation current in-creases and reaches 29.4 mA. With an increase in the concentration of hydrochloric acid from 35 to 100 g/l and a change in the voltage between the electrodes, the titanium oxidation rate increases evenly, but in the voltage range of 10–12 V, a sharp increase in the current magnitude up to 360 mA is observed. A change in the oxidation current indicates an increase in the rate of titanium dissolution. With an increase in the duration of electrolysis, the magnitude of the anode current generally decreases. In all probability, at a voltage of 14 V and higher, a breakdown of the oxide semiconductor film of titanium dioxide is observed in the hydrochloric acid solution. In this regard, a noticeable dissolution of titanium occurs and, subsequently, an oxide film is not produced, but titanium ions are produced. Visual observations have shown that titanium passes into solu-tion in the form of titanium (IV).