Anchoring (fullerol-)Ru-based-complex onto TiO₂ for Efficient Water Oxidation Catalysis

Ruthenium polypyridine complexes are the most effective catalysts for the water oxidation reaction (WOR), but the catalytic activity still has a large room for improvement. Herein, a fullerol-based ruthenium complex was prepared by the covalent grafting of the polypyridyl ruthenium complex of water oxidation catalyst (WOC) with fullerol, and the (fullerol)Ru-based WOCs anchored on the surface of nano-TiO2 were prepared through a sensitization strategy. The synthesized heterogeneous nano-catalysts are fully characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), infrared spectroscopy (IR), Brunauer-Emmett-Teller (BET) specific surface area and pore size distribution, and diffusion reflection ultraviolet-visible spectrum (DRS). The chemical oxygen evolution experiments reveal that the WOR catalyzed by the catalyst is a first-order reaction with respect to Ce (NH4)(2)(NO3)(6) (denoted as CAN) concentration when using CAN as the sacrificial oxidant under acidic conditions. The anchoring of Ru-based WOC to TiO2 result in a decrease in the redox potentials of Ru-IV/III couples, which decrease the barrier of the crucial O O bond-forming step, and the heterogeneous nano-catalyst exhibit a high catalytic activity with a turnover frequency of 13.4 s(-1) and more excellent stability with a 15-min-turn over number of 1054 for TiO2 fullerol-based ruthenium complex WOC.