Highly Active Subnanometer Au Particles Supported on TiO2 for Photocatalytic Hydrogen Evolution from a Well-Defined Organogold Precursor, [Au5(mesityl)5]

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• 作者：Georges Siddiqi ; Victor Mougel ; Christophe Copéret
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：April 18, 2016
• 年：2016
• 卷：55
• 期：8
• 页码：4026-4033
• 全文大小：442K
• 年卷期：0
• ISSN：1520-510X

文摘

A highly efficient H₂ evolution photocatalyst based on TiO₂ supported subnanometer Au particles was developed on the basis of the reaction of a gold(I) molecular precursor [Au₅Mes₅] (Mes = 2,4,6-trimethylphenyl), with titanium dioxide partially dehydroxylated at 120 °C. IR, UV–vis, elemental analysis, XANES, and STEM-EDX show that the deposition of [Au₅Mes₅] onto TiO₂ leads to the formation of both subnanometer Au particles and chemisorbed [Au₅Mes₅]. The remaining organic ligands are removed via a mild treatment under H₂, yielding subnanometer gold(0) particles. A range of Au loadings (0.3, 0.9, 2.4 wt %) with similar particle sizes (<1 nm) on TiO₂ are obtained and tested in methanol-assisted photocatalytic hydrogen production under UV light. These catalysts display significantly higher activity than a commercial reference Au-TiO₂ catalyst. The presence of chemisorbed [Au₅Mes₅] in the as-synthesized catalyst further improved activity, albeit at the expense of stability. This work demonstrates a simple synthetic route to obtain subnanometer Au particles on TiO₂ that display exceptional activity in photocatalysis.