Effects of pH on the degradation of aqueous ferricyanide by photolysis and photocatalysis under solar radiation

Results of voltammetry and spectrophotometry analyses revealed that upon sunlight exposure, the conversion of ferricyanide to ferrocyanide, and the reverse reaction, in the absence and in the presence of TiO2 catalyst depends strongly on pH. Thus, the pH of the solution dictates whether the redox reactions will proceed under illumination. In addition, the extent of the heterogeneous photocatalytic degradation of ferricyanide was influenced by pH. The initial concentration of ferricyanide did not affect its degradation.