Department of Physics and Astronomy, University of Bologna, Viale Berti-Pichat 6/2, 40127 Bologna (Italy); ESRF-The European Synchrotron, 71 Avenue des Martyres, Grenoble 38000 (France).
Angew Chem Int Ed Engl. 2015 Apr 27;54(18):5413-6. doi: 10.1002/anie.201412030. Epub 2015 Mar 6.
Exploiting plasmonic Au nanoparticles to sensitize TiO2 to visible light is a widely employed route to produce efficient photocatalysts. However, a description of the atomic and electronic structure of the semiconductor sites in which charges are injected is still not available. Such a description is of great importance in understanding the underlying physical mechanisms and to improve the design of catalysts with enhanced photoactivity. We investigated changes in the local electronic structure of Ti in pure and N-doped nanostructured TiO2 loaded with Au nanoparticles during continuous selective excitation of the Au localized surface plasmon resonance with X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). Spectral variations strongly support the presence of long-lived charges localized on Ti states at the semiconductor surface, giving rise to new laser-induced low-coordinated Ti sites.
利用等离子体金纳米粒子来敏化 TiO2 以响应可见光，是一种广泛应用的方法，可用于制备高效光催化剂。然而，对于注入电荷的半导体位置的原子和电子结构，目前仍缺乏描述。这种描述对于理解基础物理机制以及改进具有增强光活性的催化剂的设计非常重要。我们通过 X 射线吸收光谱 (XAS) 和共振非弹性 X 射线散射 (RIXS) 研究了在 Au 纳米粒子负载的纯和 N 掺杂纳米结构化 TiO2 中，Ti 的局部电子结构在持续选择性激发 Au 局域表面等离子体共振时的变化。光谱变化强烈支持在半导体表面 Ti 态上存在长寿命电荷的存在，导致新的激光诱导低配位 Ti 位的出现。
