Construction of Two Novel Titanium Oxide Clusters: Copper Ion Introducing Enhances Photocatalytic Performance

Polyoxometalates (POMs) exhibit excellent properties in many aspects; in addition to their unique geometry and electronic structures, POMs have shown outstanding catalysis, as well as magnetic and redox properties. In contrast, as a new type of polyacid system, many aspects of titanium oxide clusters (TOCs) still remain unexplored. By introducing fluorine‐substituted salicylic acid ligand into the TOCs system, we synthesized [Ti7(µ3‐O)4(LF)4(iPrO)12]·2(CH3CN) (1; LF = 3‐fluorosalicylic acid) with an Anderson‐type related structure, which is already well known for other POMs. Additionally, introducing Cu ions into the same system, we obtained [Ti6Cu2(µ3‐O)2(LF)6(CH3COO)2(CH2CN)2(iPrO)10] with dramatic improvement of the visible‐light photocatalytic performance in both the degradation of dye and the water degradation to release H2. We have obtained two novel Titanium Oxygen Clusters (TOCs): one is similar to Anderson‐type Polyoxometalates, the other is Ti‐Cu hybrid TOCs. And it was used as a catalyst in photocatalytic H2 production. Based on the analysis of experimental data and reaction mechanism, we speculate that Ti ions and Cu ions play a synergistic role in the catalytic process, which greatly improved the amount of photocatalytic H2 production.