Semiconducting Oxides to Facilitate the Conversion of Solar Energy to Chemical Fuels

The rising significance of producing useful chemical fuels from sunlight has motivated an upsurge of photochemical research, as shown by the growing diversity of chromophores, redox catalysts, and reactivity studies. However, their synergistic integration within artificial photosynthetic systems requires shareable platforms. Early transition-metal oxides have exhibited effective chromophoric/electronic properties across many systems, which has enabled outstanding photocatalytic water splitting efficiencies, but only, under ultraviolet irradiation. Semiconducting modifications of these oxides have been investigated that both extend their absorption deep into the visible region and also closely bracket the redox potentials for water splitting and carbon dioxide reduction. Their coupling to surface-anchored molecular catalysts in order to lower kinetic barriers and provide product selectivity is anticipated to lead to studies involving the dynamic interplay of photons, charge carriers, and catalyst turnover.