Pilar de Lara-Castells María, Hauser Andreas W, Ramallo-López José M, Buceta David, Giovanetti Lisandro J, López-Quintela M Arturo, Requejo Félix G
Instituto de Física Fundamental (C.S.I.C.) , Serrano 123 , Madrid , E-28006 , Spain . Email:
Graz University of Technology , Institute of Experimental Physics , Petersgasse 16 , 8010 Graz , Austria . Email:
J Mater Chem A Mater. 2019 Apr 7;7(13):7489-7500. doi: 10.1039/c9ta00994a. Epub 2019 Feb 16.
The decoration of semiconductors with subnanometer-sized clusters of metal atoms can have a strong impact on the optical properties of the support. The changes induced differ greatly from effects known for their well-studied, metallic counterparts in the nanometer range. In this work, we study the deposition of Cu clusters on a TiO surface and investigate their influence on the photon-absorption properties of TiO nanoparticles the computational modeling of a decorated rutile TiO (110) surface. Our findings are further supported by selected experiments using diffuse reflectance and X-ray absorption spectroscopy. The Cu cluster donates an electron to TiO, leading to the formation of a small polaron Ti 3d state and depopulation of Cu(3d) orbitals, successfully explaining the absorption spectroscopy measurements at the K-edge of copper. A monolayer of highly stable and well fixated Cu clusters is formed, which not only enhances the overall absorption, but also extends the absorption profile into the visible region of the solar spectrum direct photo-induced electron transfer and formation of a charge-separated state.
用亚纳米尺寸的金属原子团簇修饰半导体可以对载体的光学性质产生强烈影响。所引起的变化与在纳米范围内已得到充分研究的金属对应物的效应有很大不同。在这项工作中，我们研究了铜团簇在TiO表面的沉积，并研究了它们对TiO纳米颗粒光子吸收特性的影响——对修饰的金红石TiO(110)表面进行了计算建模。我们的发现通过使用漫反射和X射线吸收光谱的选定实验得到了进一步支持。铜团簇向TiO提供一个电子，导致形成一个小极化子Ti 3d态并使Cu(3d)轨道去填充，成功解释了在铜的K边的吸收光谱测量结果。形成了单层高度稳定且固定良好的铜团簇，这不仅增强了整体吸收，还将吸收谱扩展到太阳光谱的可见光区域——直接光致电子转移和电荷分离态的形成。
