Surface Reactions (oxidation, catalysis) and Electron Microscopy (in situ)
Dealing with oxidation is a major societal priority, yet oxidation also presents a fascinating challenge in thin film growth. Classical theories of oxidation were based mostly on thermogravimetric analysis (TGA) that only measures weight change, not structural changes. Hence, classical theories assume a uniform film growth, yet it is well known that oxides do not develop as uniform films. Recent developments of in situ experimental tools permit visualization of the dynamic processes at the nanoscale. Yang’s research group uses in situ ultra-high vacuum transmission electron microscopy (UHV-TEM) to improve the fundamental understanding of oxidation; figure 1 are bright field images of Cu and Cu-5%Ni thin films during oxidation at P(O2) 10-4 Torr in situ, where oxide islands are seen to nucleate and grow and their shapes depend sensitively on temperature. Heteroepitaxial concepts, based on surface diffusion, strain and structural evolution, describe surprisingly well these initial oxidation stages.
- "Enhanced Carbon Dioxide Electroreduction to Carbon Monoxide over Defect-Rich Plasma-Activated Silver Catalysts" Hemma Mistry, Yong-Wook Choi, Alexander Bagger, Fabian Scholten, Cecile S. Bonifacio, Ilya Sinev, Nuria J. Divins, Ioannis Zegkinoglou, Hyo Sang Jeon, Kim Kisslinger, Eric A. Stach, Judith C. Yang, Jan Rossmeisl, and Beatriz Roldan Cuenya, Angew Chem, 38, 1521 (2017)
- "Atomically Precise Gold Nanoclusters Accelerate Hydrogen Evolution over MoS2 Nanosheets: The Dual Interfacial Effect", Shuo Zhao, Renxi Jin, Yongbo Song, Hui Zhang, Stephen D. House, Judith C. Yang, and Rongchao Jin, Small, 1613 (2017)
- "High-throughput, semi-automated quantitative STEM mass measurement of supported metal nanoparticles using a conventional TEM/STEM", Stephen D. Housea, Yuxiang Chenb, Rongchao Jinb, Judith C. Yang, Ultramicroscopy, 182, 145 (2017)
- "Comparison of Spinel and Monoclinic Crystal Structures of γ-Al2O3 for Simulation of Electron Energy Loss Spectra," Henry O. Ayoola, Cecile S. Bonifacio, Qing Zhu, Dong Su, Joshua Kas, John J. Rehr, Eric A. Stach , Wissam A. Saidi , and Judith C. Yang, Microscopy and Microanalysis 23, 2020 (2017)
- "Computationally Assisted STEM and EXAFS Characterization of Tunable Rh/Au and Rh/Ag Bimetallic Nanoparticle Catalysts," Stephen D. House , Cecile S. Bonifacio , Janis Timoshenko , Pranaw Kunal , Haiqin Wan , Zhiyao Duan , Hao Li , Judith C. Yang , Anatoly I. Frenkel, Simon M. Humphrey , Richard M. Crooks , and Graeme A. Henkelman, Microscopy and Microanalysis 23, 2030 (2017)