Energy will be the Next Scientific Grand Challenge.
The past two decades have witnessed a dramatic increase in global energy consumption. While this need has been largely met by fossil fuels, the rapidly increasing global competition for this limited resource and the expectation that the Earth’s energy needs will double by 2050 and triple by the end of the century, has generated growing concern over future availability.
Combine the above with the mounting evidence that carbon dioxide emissions are adversely affecting global climate, and it becomes increasingly clear that developing renewable carbon-neutral energy sources constitutes a grand challenge for the scientific community.
To address the challenges in creating a sustainable energy future, the UNC EFRC: Center for Solar Fuels, funded by the US Department of Energy, Office of Basic Energy Sciences, was established in 2009 at one of the top five public research universities in the United States, the University of North Carolina at Chapel Hill.
Led by a distinguished faculty, including members of the National Academy of Sciences, UNC EFRC leverages key discoveries made at UNC during the past 20 years and collaborations with other research institutions to assemble a critical mass of scientists working together on energy-related research. The research center is headquartered at UNC-CH in partnership with Duke University, North Carolina Central University, North Carolina State University, the University of Florida, Research Triangle Institute, Georgia Institute of Technology and the University of Maryland.
The UNC EFRC is conducting research on capturing sunlight to drive solar fuel reactions. The Center’s efforts range from basic research on fundamental processes to integrating components into sub-systems and sub-systems into prototypical devices. The research utilizes a broad, multidisciplinary approach in a highly collaborative setting drawing on expertise across a broad range of disciplines in chemistry, physics, and materials sciences. The primary target is a Dye Sensitized Photoelectrosynthesis Cells (DSPEC) for solar fuels production as illustrated below.
Multiple platforms are under investigation but the primary focus is on Dye Sensitized Photoelectrosynthesis Cells (DSPEC). This approach utilizes molecules and molecular assemblies for catalysis in photoelectrochemical configurations closely related to those used in Dye Sensitized Solar Cells (DSSC). The Figure shows a schematic diagram for a DSPEC for light driven water reduction of CO2 to methane. In contrast to a DSSC, where the target is creating a photopotential and photocurrent, the target of a DSPEC is production of a high energy fuel with oxygen as the co-product in the physically separated compartments of a photoelectrochemical cell. The UNC EFRC focus is on a modular approach which entails constructing and maximizing component performance, as well as integration into device prototypes featuring both single and tandem light absorption.
The focus first has been on separate functions for solar fuels formation — light absorption, excited state electron and energy transfer, electron and proton transfer driven by free energy gradients, and catalysis of water oxidation and water/CO2 reduction — all integrated in a photoelectrochemical cell configuration. In the modular approach the separate components are designed and tested for maximum performance and then integrated into the final DSPEC architecture. DSPEC research benefits and is enriched by parallel research in electrocatalysis, Dye Sensitized Solar Cells, and Organic Photovoltaics.
Hallmarks of Center research are: (1) fundamental studies on reaction mechanisms, (2) synthesis of novel materials combining light absorption and catalysis, (3) preparation and characterization of designed photocatalytic interfaces, (4) application of theory and experiment to guiding principles for component design, integrated systems, and devices, and (5) augmentation of research findings and multidisciplinary strengths in collaborations with national laboratories, other EFRCs, and the Research Triangle Solar Fuels Institute.
The Center employs an integrated, interdisciplinary team-based approach in Solar Fuels based on four research areas, Catalysis, Assemblies, Interfacial Synthesis and Characterization, Device Prototypes. Ten research teams, led by faculty members at UNC and partner institutions, pursue research in these areas.
Water Oxidation Team:
Development of new solution and interfacial catalysts for water oxidation.
CO2 Reduction Team:
Development of new solution and interfacial catalysts for CO2 reduction.
Polymer Team:
Synthesis and characterization of molecular assemblies based on polymer scaffolds for multi-chromophore applications.
Peptide Team:
Molecular assemblies based on peptide scaffolds for control of chromophore/catalyst geometry.
Framework Materials Team:
Organic-inorganic hybrid materials for integrated light-harvesting and catalysis.
Interface Synthesis Team:
Synthesis and attachment of chromophore-catalyst assemblies at metal oxide interfaces.
Interface Characterization Team:
Characterization of interfacial structure and dynamics by transient and surface spectroscopies.
DSPEC Devices Team:
Evaluation and performance of integrated catalysts, assemblies and new transparent metal oxide semiconductors in device prototype configurations.
Organic Photovoltaic Devices Team:
Fabrication and characterization of devices with new approaches to 3-D charge collection.
Theory Team:
Research integrated across the Center on reaction pathways, electron and energy transport, molecular design, systems analysis.
To provide the basic research to enable a revolution in the collection and conversion of sunlight into storable solar fuels.
We will combine the best features of academic and translational research to study light/matter interactions and chemical processes for the efficient collection, transfer, and conversion of solar energy into chemical fuels.
Arey Distinguished Professor of Chemistry Thomas Meyer has been awarded the 2012 Porter Medal. This distinction is awarded every two years to the scientist who, in the opinion of the European Photochemistry Association, the Inter-American Photochemistry Society, and the Asian and Oceanian Photochemistry Association, has contributed most to the science of photochemistry with particular emphasis on more physical aspects, reflecting George Porter's own interests.