使用像差校正扫描透射电子显微镜（STEM）对负载于TiO₂纳米片上的配体保护Au₉团簇进行原子分辨结构分析。

Atomically resolved structure of ligand-protected Au9 clusters on TiO2 nanosheets using aberration-corrected STEM.

作者信息

Al Qahtani Hassan S, Kimoto Koji, Bennett Trystan, Alvino Jason F, Andersson Gunther G, Metha Gregory F, Golovko Vladimir B, Sasaki Takayoshi, Nakayama Tomonobu

机构信息

Flinders Centre for NanoScale Science and Technology, Flinders University, Adelaide SA 5001, Australia.

National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan.

出版信息

J Chem Phys. 2016 Mar 21;144(11):114703. doi: 10.1063/1.4943203.

DOI:10.1063/1.4943203

PMID:27004889

Abstract

Triphenylphosphine ligand-protected Au9 clusters deposited onto titania nanosheets show three different atomic configurations as observed by scanning transmission electron microscopy. The configurations observed are a 3-dimensional structure, corresponding to the previously proposed Au9 core of the clusters, and two pseudo-2-dimensional (pseudo-2D) structures, newly found by this work. With the help of density functional theory (DFT) calculations, the observed pseudo-2D structures are attributed to the low energy, de-ligated structures formed through interaction with the substrate. The combination of scanning transmission electron microscopy with DFT calculations thus allows identifying whether or not the deposited Au9 clusters have been de-ligated in the deposition process.

摘要

通过扫描透射电子显微镜观察发现，沉积在二氧化钛纳米片上的三苯基膦配体保护的Au9团簇呈现出三种不同的原子构型。观察到的构型一种是三维结构，对应于之前提出的团簇的Au9核心，另外两种是伪二维（pseudo-2D）结构，是这项工作新发现的。借助密度泛函理论（DFT）计算，观察到的伪二维结构归因于通过与基底相互作用形成的低能量、去配体结构。因此，扫描透射电子显微镜与DFT计算相结合能够确定沉积过程中沉积的Au9团簇是否已去配体。