NSF Award
2221965
PART 1: NON-TECHNICAL SUMMARY<br/> <br/>The need for alternative energy sources becomes essential for the growing global population with the dwindling fossil deposits on earth. Moreover, severe environmental problems caused by pollutants from fossil fuels are also imperative driving forces for seeking renewable green energy sources. It is well known that carbon dioxide reductions under sunlight and appropriate photocatalysts are a tremendous potential technology for solving the problem. With the support from the Solid State and Materials Chemistry program in the Division of Materials Research, Bangbo Yan and Pauline Norris of Western Kentucky University, a predominantly undergraduate institution, develop new metal-organic framework (MOF) materials, which contain new metal complexes with two different types of transition metal ions that are connected by an organic ligand. These materials possess an essential feature: they can absorb visible light through one type of metal center and by electron transfer, for example, catalyze carbon dioxide reduction reactions through the other type of metal center using this light energy. The principal investigators and their students study how the identity of the transition metal ions and ligands could affect the photocatalytic properties of the new MOFs. These new MOFs and fundamental materials chemistry insights gained from this study can help control climate change and carbon footprint if they are integrated into devices for harvesting solar energy and catalyzing carbon dioxide reduction in the future. Beyond these scientific and potentially technological impacts, this project also provides valuable research opportunities in STEM to undergraduates at WKU and to local high school students, including those from underrepresented groups.<br/><br/>PART 2: TECHNICAL SUMMARY<br/> <br/>For this project, which is supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the principal investigators synthesize and study novel MOFs consisting of metal-complex sensitizers and reactive centers. They hypothesize that it is possible to design MOFs that absorb visible light through one type of metal center and by electron transfer, for example, catalyze carbon dioxide reduction reactions through another type of metal center with an open metal site using this light energy. To this end they pursue three distinct objectives aimed at studying the synthesis and structure-property correlations at the fundamental materials chemistry level: The first objective is to design and study the role and effect of the identity of 3d transition metal ions in hetero-metal MOFs; the second objective is to determine the effect of changing the identity of metal ions (3d, 4d, or 5d) as a sensitizer in hetero-metal MOFs; and the third is to identify the ligand effects for hetero-metal MOFs as photocatalytic reduction of carbon dioxide. The discoveries are expected to provide an essential theory for the design and construction of new MOFs with potential applications as photocatalysts and beyond. Such new materials for solar energy harvesting and carbon dioxide reduction can potentially help control climate change and control the carbon footprint. In addition, research students (including undergraduate and high school students) receive training and education in chemistry through this research project. Through their scientific research experience, scientific writing, and presentation at regional/national conferences, students gain valuable training in critical thinking, scientific methods, writing skills, and communication skills.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
