Search

Close proximity between different catalytic sites is crucial for accelerating or even enabling many important catalytic reactions. Photooxidation and photoreduction in photocatalysis are generally separated from each other, which arises from the hole-electron separation on photocatalyst surface. Here, we show with widely studied photocatalyst Pt/TiO2 as a model, that concentrating abundant oxygen vacancies only at the metal-oxide interface can locate hole-driven oxidation sites in proximity to electron-driven reduction sites for triggering unusual reactions. Solar hydrogen production from aqueous-phase alcohols, whose hydrogen yield per photon is theoretically limited below 0.5 through conventional reactions, achieves an ultrahigh hydrogen yield per photon of 1.28 through the unusual reactions. We demonstrated that such defect engineering enables hole-driven CO oxidation at the Pt- TiO2 interface to occur, which opens up room-temperature alcohol decomposition on Pt nanoparticles to H2 and adsorbed CO, accompanying with electron-driven proton reduction on Pt to H2. [ABSTRACT FROM AUTHOR]

This work shows a novel artificial donor-catalyst- acceptor triad photosystem based on a mononuclear C5H5- RuH complex oxo-bridged TiO2 hybrid for efficient CO2 photoreduction. An impressive quantum efficiency of 0.56% for CH4 under visible-light irradiation was achieved over the triad photocatalyst, in which TiO2 and C5H5-RuH serve as the electron collector and CO2-reduction site and the photonharvester and water-oxidation site, respectively. The fast electron injection from the excited Ru2+ cation to TiO2 in ca. 0.5 ps and the slow backward charge recombination in half-life of ca. 9.8 ms result in a long-lived D+-C-A- charge-separated state responsible for the solar-fuel production. [ABSTRACT FROM AUTHOR]