Synthesis, Crystal Structures, and Photochemical Properties of a Family of Heterometallic Titanium Oxo Clusters

The incorporation of heterometallic atoms into the structure of titanium-oxygen nanomaterials is one of the known and effective strategies to develop new high-performance photovoltaic active materials. In this study, we have synthesized three benzoic acid-stabilized heterometallic titanium oxo clusters with the different transition metals Co, Cu, and Cd, formulated as [Ti4Co2(mu(2)-O)(2)(mu(3)-O)(2)(C6H5 COO)(12)(CH3CN)(2)]center dot 2CH(3) CN (1), [Ti5Cu4 (mu(3)-O)(6) (C6H5COO)(16)](2), and [Ti12Cd5(mu(2)-O)(mu(3)-O)(15) (mu(4)-O)(2)(C6H5COO)(22)(C-6 H5COOH)(CH3CN)]center dot CH3 CN center dot C-6 H5COOH (3), and then we characterized their structures. UV-vis spectroscopy analysis revealed an enhanced UV-vis-light absorption of those heterometallic clusters. The density functional theory calculations indicated that charge transfer occurs from the p orbital of O atoms to the d orbital of Ti atoms in the TiO core (O -> Ti) as well as from the metal to the core in 1 and 2. We also measured the photocurrent response and photocatalytic H-2 evolution, which shows enhancement in the photocurrent intensity and good H-2 evolution ability because of the cooperative effect of heterometal doping in titanium oxo clusters.