Ball-milled p-type CuGaO2 as a Semitransparent Scaffold for Dye-sensitized Molecular Photocathodes

Abstract CuGaO2 has limited application for dye-sensitized molecular photocathodes because of the large particle size obtained through high-temperature solid-state synthesis. Planetary ball-milling produced fine CuGaO2 particles for semitransparent electrodes while preserving the delafossite structure and Cu(I) electronic state. Photocathodes modified with a Ru tris-bipyridine-type photosensitizer exhibited enhanced photocathodic reduction currents at more positive potentials than pristine CuGaO2 and NiO electrodes despite a lower amount of immobilized dye.