A Long‐Lived Mononuclear Cyclopentadienyl Ruthenium Complex Grafted onto Anatase TiO 2 for Efficient CO 2 Photoreduction

This work shows a novel artificial donor–catalyst–acceptor triad photosystem based on a mononuclear C 5 H 5 ‐RuH complex oxo‐bridged TiO 2 hybrid for efficient CO 2 photoreduction. An impressive quantum efficiency of 0.56 % for CH 4 under visible‐light irradiation was achieved over the triad photocatalyst, in which TiO 2 and C 5 H 5 ‐RuH serve as the electron collector and CO 2 ‐reduction site and the photon‐harvester and water‐oxidation site, respectively. The fast electron injection from the excited Ru 2+ cation to TiO 2 in ca. 0.5 ps and the slow backward charge recombination in half‐life of ca. 9.8 μs result in a long‐lived D + –C–A − charge‐separated state responsible for the solar‐fuel production.