Selective Photooxidation and Photoreduction Processes at 𝐓𝐢𝐨_𝟐 Surface-Modified by Grafted Vanadyl

Figure 3

Open circuit potential decay as a function of time for illuminated electrodes: (a) TiO₂ and (b) (VO_𝑥)_𝑛/TiO₂, where the amount of vanadium loaded on TiO₂ is 3×10⁻⁷ mol (curve 1) and 5.6×10⁻⁷ mol (curve b). Electrode area: 1.1 cm². Supporting electrolyte: 1 mol L⁻¹ NaClO₄. Irradiation: 𝜆>360 nm. The inset in graph (b) refers to ESR spectra recorded on (VO_𝑥)_𝑛/TiO₂ powders illuminated at 𝜆>360 nm in the presence of 0.1 mol L⁻¹ HCOONa (see text for explanation), in the absence and in the presence of oxygen.

(a)

(b)