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

Abstract

AbstractRuthenium 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 RuIV/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.