LAUSR

Photo-driven water oxidation reaction (WOR) at nanoparticles assembled at polarized liquid–liquid interfaces is a possible realization of the anodic reaction for water splitting at chemically polarized liquid–liquid interfaces. The rational development of a photocatalyst for the WOR requires their characterization under appropriate process conditions. A micropipette filled with an aqueous dispersion of nanostructured BiVO4 as a well-defined photoactive substrate is immersed into an immiscible organic solution containing perchlorate as a common anion. Under illumination, hydroxyl radicals (OH•) are generated as adsorbed intermediates of the WOR under chemically controlled polarization. Combining the miniaturized liquid–liquid interface with a scanning electrochemical microscope allowed for the application of the surface interrogation mode for quantitative assessment of adsorbed photogenerated intermediates. The loading of OH• intermediates per projected area of the substrate (Γ = 3.33 × 10–5 mol m–2) and k...