Bao Zhi Yong, Lei Dang Yuan, Jiang Ruibin, Liu Xin, Dai Jiyan, Wang Jianfang, Chan Helen L W, Tsang Yuen Hong
Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China.
Nanoscale. 2014 Aug 7;6(15):9063-70. doi: 10.1039/c4nr00770k.
Optical probes of heterogeneous catalytic reactions are of great importance for in situ determination of the catalytic activity and monitoring of the reaction process. Surface-enhanced Raman scattering (SERS) spectroscopy could be used as a sensitive optical probe for this purpose provided that plasmonic metal nanoparticles for Raman enhancement are properly integrated with catalytic metals to form a single entity. Herein we present a facile approach for synthesizing Au@Pt core-shell nanostructures with a controllable surface density of sub-5 nm Pt nanoparticles on the surface of Au nanorods. Systematic investigations on both SERS and catalytic activities of the hybrid nanostructures reveal an optimized surface coverage of Pt. More importantly, we demonstrate that, due to their dual functionalities, the hybrid nanostructures are able to track the Pt-catalysed reaction in real time by measuring the SERS signals of the reactant, intermediate and final products. This SERS-based synergy technique provides a novel approach for quantitatively studying catalytic chemical reaction processes and is suitable for many applications such as reduction and oxidation reactions in fuel cells and catalytic water splitting.
非均相催化反应的光学探针对于原位测定催化活性和监测反应过程非常重要。如果用于拉曼增强的等离子体金属纳米颗粒与催化金属适当整合形成单一实体，表面增强拉曼散射（SERS）光谱可作为一种灵敏的光学探针用于此目的。在此，我们提出了一种简便的方法来合成金@铂核壳纳米结构，在金纳米棒表面具有可控的亚5纳米铂纳米颗粒表面密度。对混合纳米结构的SERS和催化活性的系统研究揭示了铂的最佳表面覆盖率。更重要的是，我们证明，由于其双重功能，混合纳米结构能够通过测量反应物、中间体和最终产物的SERS信号实时跟踪铂催化的反应。这种基于SERS的协同技术为定量研究催化化学反应过程提供了一种新方法，适用于许多应用，如燃料电池中的还原和氧化反应以及催化水分解。
