Photocatalytic reduction of iron (III)‎ by using pure, coupled and sensitized TiO2 in aqueous solution

الملخص EN

-–visible light in presence of atmospheric oxygen has been studied .This reaction is effective to convert harmful ions to nontoxic product in water .

Primary experiment have been done to determined optimum condition of photocatalytic reaction .Firstly experiments variable amount TiO2 concentration were used at constant Fe+3 concentration .

It was found that the ideal TiO2 concentration was equal to 0.2 gm/L .

The effect of Fe+3 concentration was studied .The highest photoreduction reaction rate was obtained at 40 ppm of Fe+3 concentration in aqueous suspension containing 0.2 gm /L TiO2 concentration .

The Langmuir – Hinshelwood kinetic model has been applied to calculate apparent rate reaction constant and adsorption constant.

The results shows the rat of photocatalytic reduction reaction was increased when TiO2 was sensitized with riboflavin photosensitizer, but the best photoreduction was obtained by using coupled CdS/TiO2 photocatalytic semiconductors.

Also half life time was calculated and the general photocatalytic reaction mechanism for this reduction process was suggested.

Keywords: TiO2 Semiconductor, photo catalytic reaction, purification of waste water by using semiconductors.