Photoelectrochemical Oxidation of Aqueous Sulfite on Ni−TiO2 Composite Film Electrodes

The photoelectrochemical oxidation of aqueous sulfite on composite electrode films comprising titania particles as the dispersed component and nickel as the matrix (Ni−TiO 2 ) is described. These composite films exhibit unusual photocurrent enhancement for sulfite oxidation relative to the corresponding neat TiO 2 films containing no nickel. Both the morphology of the composite films and their surface chemical composition (Ni:Ti ratio) are shown to play a role in the photocurrent enhancement mechanism. Two potential domains for sulfite photooxidation separated by the onset of dark oxidation of sulfite by the nickel matrix itself are considered.