Shouzhong Zou, Ph.D. - US grants

The objectives of this research are to design, fabricate, and test molecular wires, and singlemolecule
electronic devices, in particular diodes, light-activated switches and transistors, based
on dimetal inorganic complexes containing metal-metal bonds. These metal complexes provide
better control and tunability of electron transport properties as compared to organic molecules
used in molecular devices to date. The approach is to incorporate these complexes into various
two- or three-terminal nano-junctions formed by nanolithography, and to measure their electron
transport characteristics, such as rectification and amplification. The educational component
includes a jointly developed and co-taught course to train students in molecular electronics
during Spring 2005, as well as a one week summer workshop on instrumentation techniques.
The miniaturization of current silicon-based electronic devices is approaching a limit set by
physical and economical constraints. Alternative technologies, such as molecular electronics, are
required to overcome this limit and increase computation speed. Here, molecules are utilized as
conventional electronic devices. The research proposed herein explores the feasibility of using
dimetal inorganic complexes as components in molecular electronics. If successful, the proposed
research will open new avenues for designing molecular electronic devices and will provide
insight into the electron transport of molecules. The interdisciplinary nature of the proposed
research will provide students with opportunities to communicate with researchers from different
fields. The nanoscale characterization and fabrication proposed in the research will give students
hands-on experience in using state-of-the-art equipment commonly used in nanoscience and
technology. This will better prepare them for careers in this exciting research area.

The Analytical and Surface Chemistry (ASC) program of the Division of Chemistry will support the research program of Prof. Shouzhong Zou of Miami University Ohio. The study of Prof. Zou will focus on improving fuel cell technology. Prof. Zou and his students will use a new approach to fabricate model nanoparticle catalysts and study their electrocatalytic activities toward dioxygen (O2) reduction, as well as methanol and carbon monoxide (CO) oxidation, reactions that are of importance to the direct methanol fuel cell. The new fabrication method will result in well organized uniform nanoparticle arrays, and their size, composition, as well as interparticle distance will be well controlled. This could potentially improve the electrocatalytic activity and overall performance of fuel cells. The study will provide excellent training opportunities to undergraduate students, graduate students and postdoctoral researchers in a cutting edge interdisciplinary research field, which is of great importance to the US economy.

This MRI grant provides support for the acquisition of a high resolution Transmission Electron Microscope (TEM) for the Miami University Electron Microscopy Facility (EMF). The EMF is a university wide facility that is utilized extensively in teaching and research. A large number of researchers in many disciplines focus their studies on earth materials, ceramics, semiconductors, catalysts, and biological materials, and therefore TEM is an essential tool to high productivity. This new instrument will become the primary TEM for the characterization of earth materials and chemical/biological compounds. In the past 5 years, the EMF has supported funded research from 56 laboratories in 8 departments of Miami University and other regional institutions, resulting more than 126 publications. A large percent of this usage is with our severely outdated TEM. The new instrument will provide essential capabilities and will be the primary focus of multiple research programs within the campus. The improved resolution and contrast, and the new energy filtering, analytical capabilities and electron diffraction will significantly increase the types of samples that can be analyzed and the types of information obtainable. An enhanced EMF also provides many educational opportunities. The new instrument will be used to train students at all levels. About 30 students and post-docs use TEM. Most faculty have undergraduate students working in their labs. This instrument will be incorporated into the existing courses and will be used to develop new ones. The broader impact will be maximized by using Internet Tele-microscopy. Existing collaborations with other universities and industries will be strengthened and new ones will be established.

With this award from the Chemical Catalysis Program in the Chemistry Division, Professor Shouzhong Zou of Miami University will carry out studies of the relationships between nanocrystal structure and catalytic activity. Dr. Zou and his students will study electrocatalytic activity of shape, size and composition controlled platinum and platinum-based alloy nanocrystals towards reactions of importance in low temperature fuel cells, using a combination of conventional electrochemical methods, surface vibration spectroscopy, and single particle electrochemistry. Fundamental insights of catalyst structure-activity relationships gained from these studies will aid in rational design and development of highly active and durable fuel cell catalysts, and breaking the bottlenecks in the development and deployment of low temperature fuel cells.

One of the key technical challenges in fuel cell development and commercialization is to find low-cost, highly-efficient catalysts having a long lifetime. By identifying the structural factors dictating the catalytic activity of nanoscale catalysts toward fuel cell reactions, the proposed research directly addresses this pressing issue and will make significant advances in energy conversion in fuel cells. The concepts developed in this research will be applicable to other important structure sensitive reactions as well. In addition this research program will train postdoctoral researchers, graduate students and undergraduate students in electrocatalysis and fuel cells, and will also provide outreach to high schools through a teacher-researcher program.

With this award from the Major Research Instrumentation (MRI) and Chemistry Research Instrumentation and Facilities (CRIF) programs Professor Shouzhong Zou from American University and colleagues Colin Saldanha, Matthew Hartings and Douglas Fox have acquired an analytical transmission electron microscope (TEM). A TEM propels a beam of electrons at a thin sample. The electrons interact with the material to produce an image of the substance much as an optical microscope. However, the magnification is typically better than with optical microscopes. The microscope is used in a broad area of fields from materials research, to chemistry and biology to medicine. The microscopic knowledge gleamed from the TEM images can help understand the properties of the material and perhaps improve them. At American University the TEM is used to advance a number of research projects and it also impacts undergraduate research training and it is used in lecture and laboratory courses. It is also used in outreach activities to local institutions such as the University of the District of Columbia and Montgomery College to further enhance research and student training.

The proposal is aimed at enhancing research and education at all levels, especially in areas such as (a) revealing structure-catalytic activity relationships of catalysts for fuel cell reactions, carbon dioxide to organic fuel conversion and gas sensing, (b) understanding formation mechanisms and exploring structure-function properties of polymer-nanocomand organic ligand-stabilized noble metal nanoparticles, (c) developing advanced functional materials for water purification and disease detection, (d) understanding the expression and regulation of synaptic aromatase that synthesizes estrogens, (e) exploring structural modifications of retina associated with ambient light conditions and (f) revealing the reproductive system structure of decapod crustaceans.