Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) , Daejeon 34141, Republic of Korea.
Nano Lett. 2016 Mar 9;16(3):1650-6. doi: 10.1021/acs.nanolett.5b04506. Epub 2016 Feb 29.
Direct detection of hot electrons generated by exothermic surface reactions on nanocatalysts is an effective strategy to obtain insight into electronic excitation during chemical reactions. For this purpose, we fabricated a novel catalytic nanodiode based on a Schottky junction between a single layer of graphene and an n-type TiO2 layer that enables the detection of hot electron flows produced by hydrogen oxidation on Pt nanoparticles. By making a comparative analysis of data obtained from measuring the hot electron current (chemicurrent) and turnover frequency, we demonstrate that graphene's unique electronic structure and extraordinary material properties, including its atomically thin nature and ballistic electron transport, allow improved conductivity at the interface between the catalytic Pt nanoparticles and the support. Thereby, graphene-based nanodiodes offer an effective and facile way to approach the study of chemical energy conversion mechanisms in composite catalysts with carbon-based supports.
直接检测纳米催化剂上放热气相表面反应产生的热电子是深入了解化学反应中电子激发的有效策略。为此，我们制造了一种新型的基于单层石墨烯和 n 型 TiO2 层之间肖特基结的催化纳二极管，该纳二极管可检测 Pt 纳米粒子上氢氧化产生的热电子流。通过对比测量热电子电流（化学电流）和周转频率获得的数据，我们证明了石墨烯独特的电子结构和非凡的材料特性，包括其原子级薄的性质和弹道电子输运，提高了催化 Pt 纳米粒子和支撑体之间界面的导电性。因此，基于石墨烯的纳二极管为研究具有碳基支撑体的复合催化剂中的化学能量转换机制提供了一种有效且简便的方法。
