Porkovich Alexander, Ziadi Zakaria, Kumar Pawan, Kioseoglou Joseph, Jian Nan, Weng Lin, Steinhauer Stephan, Vernieres Jerome, Grammatikopoulos Panagiotis, Sowwan Mukhles
Nanoparticles by Design Unit , Okinawa Institute of Science and Technology (OIST) Graduate University , 1919-1 Tancha, Onna-Son , Okinawa 904-0495 , Japan.
Department of Physics , Aristotle University of Thessaloniki , GR-54124 Thessaloniki , Greece.
ACS Nano. 2019 Nov 26;13(11):12425-12437. doi: 10.1021/acsnano.9b06224. Epub 2019 Oct 8.
Surface charge and charge transfer between nanoclusters and oxide supports are of paramount importance to catalysis, surface plasmonics, and optical energy harvesting areas. At present, high-energy X-rays and theoretical investigation are always required to determine the chemical state changes in the nanoclusters and the oxide supports, as well as the underlying transfer charge between them. This work presents the idea of using chrono-conductometric measurements to determine the chemical states of the Ru nanoclusters on CuO supports. Both icosahedral and single-crystal hexagonal close-packed Ru nanoclusters were deposited through gas-phase synthesis. To study the charge transfer phenomenon at the interface, a bias was applied to cupric oxide nanowires with metallic nanocluster decoration. conductometric measurements were performed to observe the evolution of Ru into RuO under heating conditions. Structural elucidation techniques such as transmission electron microscopy, X-ray photoelectron spectroscopy, and Kelvin probe force microscopy were employed to study the corresponding progression of structure, chemical ordering, and surface potential, respectively, as Ru(0) was oxidized to RuO on the supporting oxide surface. Experimental and theoretical investigation of charge transfer between the nanocluster and oxide support highlighted the importance of metallic character and structure of the nanoclusters on the interfacial charge transfer, thus allowing the investigation of surface charge behavior on oxide-supported catalysts, , during catalytic operation conductometric measurements.
纳米团簇与氧化物载体之间的表面电荷及电荷转移对于催化、表面等离子体激元以及光能收集领域至关重要。目前，总是需要高能X射线和理论研究来确定纳米团簇和氧化物载体中的化学状态变化，以及它们之间潜在的电荷转移。这项工作提出了利用计时电导测量来确定CuO载体上Ru纳米团簇化学状态的想法。通过气相合成法沉积了二十面体和单晶六方密堆积的Ru纳米团簇。为了研究界面处的电荷转移现象，对带有金属纳米团簇修饰的氧化铜纳米线施加偏压。进行电导测量以观察加热条件下Ru向RuO的演变。当Ru(0)在载体氧化物表面被氧化为RuO时，分别采用透射电子显微镜、X射线光电子能谱和开尔文探针力显微镜等结构解析技术来研究结构、化学有序性和表面电位的相应变化。对纳米团簇与氧化物载体之间电荷转移的实验和理论研究突出了纳米团簇的金属特性和结构对界面电荷转移的重要性，从而能够在催化操作过程中通过电导测量研究氧化物负载催化剂上的表面电荷行为。
