CuOx–TiO2 junction: what is the active component for photocatalytic H2 production?
CuOx based junctions e.g. CuOx–TiO2 have been demonstrated to be very effective in photocatalytic H2 production, but the active component at the junction is less understood. We herein report that an as-prepared CuOx–TiO2 photocatalyst undergoes an in situ restructuring process during photocatalytic H2 production under solar light irradiation to form the active Cu2O–TiO2 interfacial structure on the surface. These results unambiguously demonstrate that Cu2O is the active copper species in CuOx–TiO2 photocatalysts.