United States Department of Energy, National Energy Technology Laboratory, Pittsburgh, Pennsylvania 15236, USA.
J Am Chem Soc. 2013 Jun 19;135(24):9015-22. doi: 10.1021/ja402887v. Epub 2013 Jun 5.
The unique physical and chemical properties of single-walled carbon nanotubes (SWNTs) make them ideal building blocks for the construction of hybrid nanostructures. In addition to increasing the material complexity and functionality, SWNTs can probe the interfacial processes in the hybrid system. In this work, SWNT-TiO2 core/shell hybrid nanostructures were found to exhibit unique electrical behavior in response to UV illumination and acetone vapors. By experimental and theoretical studies of UV and acetone sensitivities of different SWNT-TiO2 hybrid systems, we established a fundamental understanding on the interfacial charge transfer between photoexcited TiO2 and SWNTs as well as the mechanism of acetone sensing. We further demonstrated a practical application of photoinduced acetone sensitivity by fabricating a microsized room temperature acetone sensor that showed fast, linear, and reversible detection of acetone vapors with concentrations in few parts per million range.
单壁碳纳米管（SWNTs）独特的物理和化学性质使其成为构建杂化纳米结构的理想构建块。除了增加材料的复杂性和功能性外，SWNTs 还可以探测杂化系统中的界面过程。在这项工作中，发现 SWNT-TiO2 核/壳杂化纳米结构在响应紫外光照射和丙酮蒸气时表现出独特的电行为。通过对不同 SWNT-TiO2 杂化系统的紫外光和丙酮敏感性的实验和理论研究，我们对光激发 TiO2 和 SWNTs 之间的界面电荷转移以及丙酮传感机制有了基本的了解。我们进一步通过构建微尺寸室温丙酮传感器展示了光诱导丙酮敏感性的实际应用，该传感器对浓度在百万分之几范围内的丙酮蒸气具有快速、线性和可逆的检测能力。
