Materials Discovery, Design and Synthesis
- Chemical and Mechanical Properties of Surfaces, Interfaces and Nanostructures
- Inorganic-Organic Nanocomposites
- Physical Chemistry of Inorganic Nanostructures
- Adaptive Interfacial Assemblies Towards Structuring Liquids
The goal of this program is to carry out atomic and molecular level studies of surfaces and interfaces with gases, liquids and solids, focusing on structure, adsorption, and reactions, to obtain a fundamental understanding of the mechanisms that govern the physical, chemical, catalytic and mechanical properties of materials for applications to tribology, catalysis, solar energy, fuel cells and energy storage. We study how the structure of surfaces determines these properties, and how energy is transferred by vibrational, electronic and photonic excitations of surface atoms and molecules. To that effect we use single crystals, thin films, and nanoparticles of controlled size, shape and composition. Synthetic strategies are developed to grow and control the size and shape of nanocrystals of metals, alloys and oxides. An important activity of the program is the continuous development and improvement of instruments, techniques and methods that make possible microscopy and spectroscopy studies of interfaces in all environments, from vacuum to ambient gas pressures, and liquids, and high with surface sensitive. These include sum frequency generation (SFG) vibrational spectroscopy, high-pressure scanning tunneling microscopy (HP-STM), and synchrotron-based techniques such as ambient pressure x-ray photoelectron spectroscopy (AP-XPS), and x-ray absorption spectroscopy (XAS).
Zhiqiang Niu, Nigel Becknell, Yi Yu, Dohyung Kim, Chen Chen, Nikolay Kornienko, Gabor A. Somorjai and Peidong Yang. Anisotropic Phase Segregation and Migration of Pt in Nanocrystals en route to Nanoframe Catalysts. Nature Materials (2016).
Ji Su, Chenlu Xie, Chen Chen, Yi Yu, Griffin Kennedy, Gabor A. Somorjai and Peidong Yang. Insights into the Mechanism of Tandem Alkene Hydroformylation over Nanocrystalline Catalyst with Multiple Interfaces. J. Am. Chem. Soc. 138, 11568-11574 (2016).
Eren, Baran; Weatherup, Robert; Liakakos, Nikos; Somorjai, Gabor; Salmeron, Miquel. Dissociative Carbon Dioxide Adsorption and Morphological Changes on Cu(100) at Ambient Pressures. J. Am. Chem. Soc. 138 (26), 8207-8211 (2016).
The organic/inorganic nanocomposite program aims to design and synthesize organic and inorganic building blocks, and guide their assemblies into functional nanocomposite materials by developing a thorough understanding of interfacial electronic properties with an ultimate goal to generate functional hybrid materials with tailored electrical and optical properties.
M. Scheele, D. Hanifi, D. Zherebetskyy, S. T. Chourou, S. Axnanda, B. J. Rancatore, K. Thorkelsson, T. Xu, Z. Liu, L.-W. Wang, Y. Liu, and A. P. Alivisatos. PbS Nanoparticles Capped with Tetrathiafulvalenetetracarboxylate: Utilizing Energy Level Alignment for Efficient Carrier Transport. ACS Nano 8, 2532 (2014).
J.H. Engel, Y. Surendranath, and A.P. Alivisatos. Controlled doping of semiconductor nanocrystals using redox buffers. J. Am. Chem. Soc.134(32), 13200-13203 (2012).
J. Kao, S. J. Jeong, Z. Jiang, D. H. Lee, K. Aissou, C. A. Ross, T. P. Russell, and T. Xu. Direct 3-D Nanoparticle Assemblies in Thin Films via Topographically Patterned Surfaces. Advanced Materials 26(18), 2777-2781 (2014).
S. N. Raja, A. C. K. Olson, K. Thorkelsson, A. J. Luong, L. Hsueh, G. Chang, B. Gludovatz, L. Lin, T. Xu, R. O. Ritchie, and A. P. Alivisatos. Tetrapod Nanocrystals as Fluorescent Stress Probes for Electrospun Nanocomposites. Nano Letters, 13(8), 3915-3922, (2013).
This program works to advance the synthetic control of nanocrystals and nanowires for their use in integrated systems; to establish core science and technology for producing, separating, and transporting charges; and to measure and interpret the interactions of nanostructured materials at interfaces, including inorganic-organic, semiconductor-semiconductor, and semiconductor-catalyst interfaces.
D Zhang, Y Yang, Y Bekenstein, Y Yu, NA Gibson, AB Wong, SW Eaton, N Kornienko, Q Kong, M-L Lai, AP Alivisatos, SR Leone and P Yang. Synthesis of Composition Tunable and Highly Luminescent Cesium Lead Halide Nanowires through Anion-Exchange Reactions. J. Am. Chem. Soc. 138 (23), pp 7236-7239 (2016).
N Kornienko, NA Gibson, H Zhang, SW Eaton, Y Yu, S Aloni, SR Leone and P Yang. Growth and Photoelectrochemical Energy Conversion of Wurtzite Indium Phosphide Nanowire Arrays. ACS Nano 10 (5), pp 5525-5535 (2016).
SW Eaton, M Lai, N Gibson, AB Wong, L Dou, J Ma, LW Wang, SR Leone and P Yang. Lasing in Robust Cesium Lead Halide Nanowires. Proc. Natl. Acad. Sci. U.S.A. 113 (8), pp 1993-1998 (2016).
There has been little success in producing materials with dynamic response that spans from liquids to solids, which can address many challenges in next-generation energy technologies. This program focuses on developing a new class of materials, "Structured Liquids", generated by the interfacial formation, assembly and jamming of nanoparticle surfactants. By manipulating the interfacial packing of the NP surfactants using external triggers, to generate a new family of materials that synergistically combines the desirable characteristics of fluids-rapid transport of energy carriers (e.g. electrons or protons), conformability to arbitrary shapes, and controlled dissipation of mechanical energy-with the structural stability of a solid. The results from these studies will lead to revolutionary design strategies for directing the flow of mechanical, electrical or optical energy in materials or systems. We will develop dynamic covalent bonding chemistries and quantitatively characterize nanoparticle assemblies and their dynamic responses across multiple length and time scales. The percolated pathways formed by the jammed NPs present further opportunities to capitalize on the inherent electrical, thermal or plasmonic properties of NPs. Using advanced microscopies, electron and scanning probe, the two dimensional assemblies of nanoparticle surfactants will allow us to address long-standing fundamental problems in glassy materials.
A. Toor, T, Feng and T.P. Russell. Self-assembly of nanomaterials at fluid interfaces. Eur. Phys. J. E 39, 57 (2016).
C. Hang, Z. Sun, M. Cui, F. Liu, B.A.Helms and T. P. Russell. Structured Liquids with pH-Triggered Reconfigurability. Adv. Mat., 28(11), 6612 (2016).