Instituto de Física Fundamental (C.S.I.C.), Serrano 123, E-28006, Madrid, Spain.
Instituto de Estructura de la Materia (C.S.I.C.), Serrano 123, E-28006, Madrid, Spain.
Phys Chem Chem Phys. 2018 Jul 18;20(28):19110-19119. doi: 10.1039/c8cp02853b.
A first-principles study of the stability and optical response of subnanometer silver clusters Agn (n ≤ 5) on a TiO2(110) surface is presented. First, the adequacy of the vdW-corrected DFT-D3 approach is assessed using the domain-based pair natural orbital correlation DLPNO-CCSD(T) calculations along with the Symmetry-Adapted Perturbation Theory [SAPT(DFT)] applied to a cluster model. Next, using the DFT-D3 treatment with a periodic slab model, we analyze the interaction energies of the atomic silver clusters with the TiO2(110) surface. Finally, the hybrid HSE06 functional and a reduced density matrix treatment are applied to obtain the projected electronic density of states and photo-absorption spectra of the TiO2(110) surface, with and without adsorbed silver clusters. Our results show the stability of the supported clusters, the enhanced light absorbance intensity of the material upon their deposition, and the appearance of intense secondary broad peaks in the near-infrared and the visible regions of the spectrum, with positions depending on the size and shape of the supported clusters. The secondary peaks arise from the photo-induced transfer of electrons from intra-band valence 5s orbitals of the noble-metal cluster to 3d Ti band states of the supporting material.
采用基于域的对自然轨道相关的 DLPNO-CCSD(T)计算以及基于对称自适应微扰理论(SAPT(DFT))的方法，对团簇模型进行了计算，评估了使用 vdW 修正的 DFT-D3 方法的充分性。接下来，采用 DFT-D3 处理方法和周期性平板模型，分析了原子银团簇与 TiO2(110)表面的相互作用能。最后，采用混合 HSE06 泛函和简化密度矩阵处理方法，获得了吸附银团簇前后 TiO2(110)表面的投影电子态密度和光吸收谱。我们的研究结果表明，负载的团簇是稳定的，材料的光吸收率在沉积银团簇后增强，并且在光谱的近红外和可见光区域出现强烈的二次宽峰，其位置取决于负载团簇的尺寸和形状。这些次级峰源于光诱导的从贵金属团簇的内带价 5s 轨道到支撑材料的 3d Ti 带态的电子转移。
