Department of Chemistry, ⊥Department of Physics and Astronomy, and ||Department of Geosciences, University of Missouri-Kansas City , Kansas City, Missouri 64110, United States.
ACS Appl Mater Interfaces. 2013 Oct 23;5(20):9883-90. doi: 10.1021/am402983k. Epub 2013 Oct 4.
Understanding the structures and properties of interfaces in (nano-)composites helps to reveal their important influence on reactivity and overall performance. TiO2 is a technologically important material, and anatase/rutile TiO2 composites have been shown to display enhanced photocatalytic performance over pure anatase or rutile TiO2. This has been attributed to a synergistic effect between the two phases, but the origin of this effect as well as the structure of the interface has not been established. Using Raman spectroscopy, here we provide evidence of distinct differences in the thermal properties of the anatase and rutile moieties in the composite, with anatase becoming effectively much warmer than the rutile phase under laser irradiation. With the help of first-principles calculations, we analyze the atomic structure and unique electronic properties of the composite and infer possible reasons for the directional heat dissipation across the interface.
了解（纳米）复合材料中界面的结构和性质有助于揭示它们对反应性和整体性能的重要影响。TiO2 是一种具有重要技术意义的材料，已证明锐钛矿/金红石 TiO2 复合材料在光催化性能方面优于纯锐钛矿或金红石 TiO2。这归因于两相之间的协同效应，但这种效应的起源以及界面的结构尚未确定。本文使用拉曼光谱，提供了复合材料中锐钛矿和金红石部分热性质明显差异的证据，在激光辐照下，锐钛矿的温度明显高于金红石相。借助第一性原理计算，我们分析了复合材料的原子结构和独特的电子性质，并推断了界面上定向散热的可能原因。
