Clemens Burda, Ph.D. - US grants

In this CAREER project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Burda will study ternary semiconductor nanodots using nanoparticle synthesis and chemometric modeling, detailed characterization of optoelectronic properties by laser spectroscopy, and device fabrication and application-specific efficiency measurements. The fabrication of nanoparticles is based on two different families of materials, namely compounds of the type Cu(In,Ga)(S,Se,Te)2 and TiO(2-x)N(x). Characterization techniques include high-resolution transmission microscopy (EDS and EELS) and nanosecond-to-femtosecond spectroscopic measurements. In the end the investigator will fabricate photovoltaic devices using nanoparticles of the two types synthesized in this research. The educational activities of this project include involvement in the "Math and Science Partnership" (MSP) Outreach Program for Local High School Teachers, educational workshop programs of the NASA Glenn Research Center, and collaborative outreach projects. Undergraduate students and students from the local high school will be able to participate in the research experience of the PI's laboratory. A new course for undergraduates on the topic of nanomaterials will introduce students from different scientific backgrounds (engineers, chemists and physicists) to developments in the interdisciplinary field of nanoscience.

Understanding and controlling the optoelectronic properties of ternary semiconductor nanomaterials is of great interest to many important technological applications, such as fabrication of photovoltaic solar cells and lasers as well as semiconductor-based photocatalysis. The outreach activities impact education from grades K-12 through postdoctoral training and from local to national arenas.

With support from the Chemistry Research Instrumentation and Facilities: Departmental Multi-User Instrumentation (CRIF:MU) Program, the Department of Chemistry at Case Western Reserve University will acquire a set of ultrafast lasers and associated instrumentation to build the experimental capability in a new Center for Chemical Dynamics (CCD). This equipment will allow researchers to pursue a large number of state-of-the-art experiments in photophysical and photochemical research. Addition of the new instrumentation in the CCD is expected to impact important research areas such as proteomics, photodynamic and other therapeutic designs, chemical biology, molecular electronics and computing, photo- and electroactive materials, and nanomaterials. The instrumentation will be used in formal and informal laboratory settings to engage undergraduate students at Case in research-quality, time-resolved spectroscopy of photoactive systems. In the future, this undergraduate research initiative will be expanded to bring students at other institutions to the CCD for summer programs. These efforts will provide research experience at the undergraduate level through senior capstone projects and traditional undergraduate research (initially, 30-40 BS and BA Chemistry majors per year at Case).

Ultrafast laser spectroscopy provides a powerful probe of molecular information. Many chemical and biological processes occur on the femtosecond time scale, including electron transfer, photochemical reactions, and molecular energy dynamics. The CCD is a new effort at Case to foster world-class research into chemical dynamics in its central applications to the physical sciences, engineering and biomedical fields.

Abstract

Proposal Title: NIRT: Active Nanoparticles in Nanostructured Materials Enabling Advances in Renewable Energy and Environmental Remediation

Proposal Number: CTS-0608896

Principal Investigator: David A. Dixon

Institution: University of Alabama Tuscaloosa

Analysis (rationale for decision):



This project will utilize new synthesis advances to develop catalytic materials for photo-electrochemical reactions with the aim of advancing renewable energy production and environmental remediation. Active nanostructured materials enable the development of new paradigms for the modification of interfaces which readily allow the generation of enhanced catalytic and sensing capabilities due to their uniquely confined structural and electronic properties. This integrated multidisciplinary program includes the synthesis of new nanomaterials that can undergo controllable changes, measurements of these changes, and the use of advanced computational methods to understand such changes in order to provide the most insight into how to control and utilize active nanostructured systems for practical technological applications. The overall approach is based on two recent synthetic advances by this team to generate nanoparticles and new nanostructures, which can be decorated by them. The first is the development of new compounds/materials for photo-electrochemical reactions. The second key advance has involved the development of porous silicon conductometric sensors. A key application area is the use of nanoparticles of TiO2, which have been modified by the addition of nitrogen to form the oxynitride, TiO2-xNx. This shifts the energy of the effective band gap of TiO2 so as to create a better photocatalytic absorber of photons in the visible part of the spectrum. In addition, these nanoparticles can be doped with metal ions to change how they interact with ligands such as water or organic molecules. A goal of the proposed effort is to use seeded nanostructured particles incorporated into hybrid micro/nano-structured environments as photocatalysts for: (1) the production of H2 from water splitting or from the gas-shift reaction and (2) the destruction of organic compounds in aqueous waste streams. A critical goal of the work is to utilize an integrated experimental and computational approach to understand the behavior of the catalytically active nanostructures, especially as they change structures and develop new properties in their active state.

Graduate students, and undergraduate students participating in the program will acquire training on sophisticated instrumentation as they pursue new fundamental knowledge in complementary fields that will enable them to study the fundamental behavior of active nanostructures. They will leave with improved problem solving skills and greater scientific independence, and thus be better positioned to contribute to the national effort in science and technology. In addition, the student researchers will be exposed to a new interdisciplinary approach that will involve extensive collaboration with other universities and laboratories in the area of understanding the behavior of active nanoparticles. Undergraduates will be directly involved in the research program through the Honors College at The University of Alabama and the undergraduate programs at Case-Western and Georgia Tech. Involvement in the program of members of underrepresented groups will continue to be encouraged, and proactive efforts will be made to recruit members of these groups, particularly those early in their scientific careers. Minority students will be involved in the research through outreach programs at the participating institutions and through summer REU programs at the institutions. All participants in the project will be expected to contribute to the dissemination of research results in the scientific literature and at conferences.