PI: Nitin Chopra, Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa. This research endeavor focuses on novel multi-functional and multi-component analytical and detection devices based on graphene encapsulated noble metal nanoparticles (GE-NMPs). Fabrication of a continuous and non-porous graphene shell offers a unique way to stabilize noble metal nanoparticles (NMPs) lending multi-functionality and unique properties to these hybrid nanomaterials. Such nanomaterials are of enormous importance for homeland and border security, sensor industry, and analytical device technology. The research involves studies on the growth of GE-NMPs and their nanowire-based heterostructures using a chemical vapor deposition (CVD) process. The information will be broadly applicable to many materials systems that have an ability to catalyze carbon growth and will be a notable advancement in the area of novel graphene-based nanomaterials and devices. These materials are highly robust and can be readily functionalized for further applications. The approach is to fully utilize the functions of the individual components (graphene and noble metal nanoparticle) to locate, detect, separate, and assemble chemical species with enhanced signals. In addition, hybrid nanomaterials will be vital in realizing advanced engineering applications, including, chemical and biological sensors and novel spectroscopy substrates that integrate a uniquely heterostructured nano-electromechanical system (NEMS). These devices will have high resolution, chemical selectivity, improved sensitivity and detection limits, reversibility, and robustness. The research program is multidisciplinary and has strong fundamental and technological components allowing students to work and gain experience in cutting edge nanotechnology research.

Project Report

The research under this program resulted in new kinds of multi-functional and multi-component analytical and detection nanosystems based on graphene encapsulated noble metal nanoparticles (GE-NMPs). The studies led to a fundamental understanding of graphene shell encapsulating Au, Pd, or Pt nanoparticles (NPs) and the growth of new kinds of GE-NMP based heterostructures. These systems employed rich graphene chemistry and properties of nanoparticles to achieve desired functions. For example, the developed substrates allowed locating, detecting, separating, and assembling chemical species with enhanced signals. The outcomes have strong implications for surface enhanced Raman spectroscopy (SERS) with GE-NMPs serving as superior and sensitive substrates. These hybrid nanomaterial-based devices will be a vital development for advanced engineering applications. Apart from experimental work, the project included mathematical modeling to understand the optical properties of the hybrid nanomaterials. The project also resulted in the understanding of molecule-surface interactions, thermal properties, and opto-electronic characteristics of hybrid nanoscale heterostructures. Intellectual merits: The intellectual merit of this research lies in the fundamental understanding of novel hybrid nanomaterials composed of GE-NMPs and heterostructured devices based on the same. It fills a critical knowledge gap starting from growing graphene shells on inert material nanoparticles through a scalable approach to modulation of properties of such systems by creating novel assemblies and higher order heterostructures as well as applications of these hybrid nanoparticles. This project includes synthesis and exploration of new hybrid nanomaterials, understanding the role of NMPs in catalyzing graphene shell growth, focusing on morphological, chemical, microscopic, and spectroscopic properties. Such multi-functional heterostructures and nanomaterials showed properties and characteristics extremely useful for analytical and sensing devices, multi-functional platforms, and novel SERS substrates. The project has advanced the knowledge in the field of curved or spherical graphene-based heterostructures. The PI, Professor Nitin Chopra, an experimental materials scientist with experience in nanomaterials growth and applications, established the laboratory to perform the research and trained and mentored all the participants. The project is potentially transformative and will impact areas of sensors and optical devices. Two patent disclosures are filed and a provisional patent is filed with the University of Alabama’s office of technology transfer. The proposed activity was very well-conceived and organized by the PI. The graduate and undergraduate students, visiting scientist, high school students were propelled towards next steps in their careers. The research also allowed for the development of new infrastructure in the PI’s lab. Broader Impact: The multi-component and multi-functional GE-NMPs and their heterostructures are of enormous importance for homeland and border security, sensor industry, and analytical device technology. The research work benefits our society in a number of ways by ensuring safety and security and by utilizing fundamental science to fulfill the needs of real-life situations. The research was multidisciplinary, integrating students within the area of nanotechnology from the departments of Metallurgical and Materials Engineering and Materials Science at The University of Alabama. This program involved strong fundamental as well as technological components. The involved students benefited by actively learning state-of-the-art nanotechnology tools, completed Masters and PhDs, and obtained high-profile jobs. The integration of undergraduate students from the university and neighboring HBCU’s helped in the enhancement of their professional and intellectual abilities. These also motivated students to pursue graduate studies propelling them towards research careers, impacting these disciplines nationally. The project has resulted in more than 23 research articles, 7 journal editorials, 3 book reviews, 12 conference proceedings, 2 book chapters, and more than 40 invited talks and numerous conference abstracts/presentations. The PI mentored 4 GRAs (one minority student), 7 UGs, 6 high school students, and 2 high school teachers, including female minority students. The interns,co-authored peer-reviewed journal articles in Carbon, Journal of Nano Education, Materials Characterization, and Journal of Nanoparticle Research. 3 MS and 2 PhDs were completed. GRAs and interns won conference awards and a scholarship. The research resulting from this project is an integral part of the nanoscience lectures and laboratory demonstrations in the PI’s group at HBCU and SECME workshops and local high schools. The PI started a new symposium on nanoscale heterostructures at the TMS annual meeting. The PI developed a new course in Nanomaterials processing, properties, and applications (MTE 691) and added several components on nanoscale heterostructures to the existing courses in the department. The new courses, developed under this program, were the first of its kind at UA and attracted students with diverse backgrounds. The PI has done significant outreach with high schools, museums, and the community such as Nanotechnology Science Café and High School nanotechnology workshop.

Agency
National Science Foundation (NSF)
Institute
Division of Electrical, Communications and Cyber Systems (ECCS)
Application #
0925445
Program Officer
Paul Werbos
Project Start
Project End
Budget Start
2009-09-15
Budget End
2013-08-31
Support Year
Fiscal Year
2009
Total Cost
$342,625
Indirect Cost
Name
University of Alabama Tuscaloosa
Department
Type
DUNS #
City
Tuscaloosa
State
AL
Country
United States
Zip Code
35487