Fe/TiO2 composite coatings modified by ceria layer: Electrochemical synthesis using environmentally friendly methanesulfonate electrolytes and application as photocatalysts for organic dyes degradation
By Protsenko, V. S.; Vasil
Published in Journal of Environmental Chemical Engineering
2017
Abstract
Abstract This work reports the results of our effort to manufacture Fe/TiO2 electrodeposited composite coatings modified by ceria layer and use them as heterogeneous photocatalysts for the decomposition of some organic dyes. Iron electrodeposited matrix may be a cheap, available, nontoxic and easily repairable support for TiO2 photocatalysts, however, it is not corrosion-resisting enough. In order to improve the corrosion stability, as-deposited Fe/TiO2 (5% wt. of titania) composite coatings obtained from a methanesulfonate iron plating bath were modified by cathodic treatment in solution containing cerium (III) methanesulfonate. As a result, a very thin layer of cerium oxides was formed on the surface of Fe matrix. The corrosion resistance of iron/titania coatings after their modification by ceria film was studied by means of voltammetry method and electrochemical impedance spectroscopy. The surface modification of Fe/TiO2 composites by ceria layer resulted in a significant increase in their corrosion stability which allows their practical application as photocatalysts for wastewater treatment. The photocatalytic properties of TiO2 particles immobilized on Fe/TiO2 composite electrodeposits modified by ceria layers were tested in the reaction of photochemical degradation of methyl orange (MO) and methylene blue (MB) dyes in water under the action of {UV} radiation. The apparent rate constants of {MO} and {MB} photodegradation at natural pH values were 0.0018 and 0.0056 min?1, respectively. Thus we developed a new technique of TiO2 particles immobilization for advanced oxidation processes, which involves electrodeposited composite coatings with Fe matrix.