The Powering the Planet (PP) Chemical Bonding Center focuses on one of the "Grand Challenges" for the 21st Century: the efficient, and ultimately economical, conversion of solar energy into stored chemical fuels. PP efforts will focus on developing the components for a solar water splitting system. These components are: (i) a membrane-supported assembly that captures sunlight and then efficiently separates and transports charge, (ii) a two-electron catalyst that reduces water to hydrogen, and (iii) a four-electron catalyst that oxidizes water to oxygen. This interdisciplinary effort will involve semiconductor materials, polymeric and inorganic membranes, synthesis, theory, and mechanistic chemistry. The basic science pursued in PP will provide the foundation for future carbon-neutral energy technologies.
PP will train a diverse and talented pool of students in the technical skills needed for the solution of this critical challenge. PP will incorporate underrepresented groups through partnering with specific undergraduate institutions and providing broad access to PP research scientists through both direct and virtual (videoconference) interactions. Outside of the laboratory, PP participants will help develop innovative curricula for high school, undergraduate, and graduate students. PP researchers will raise the public's awareness of the challenges of the energy problem, how solar energy can contribute to its solution, the nature of the fundamental scientific challenges in developing a water-splitting device, and the impact of PP research through public lectures, national TV and radio programs. Further, PP PIs will work with several major business leaders and companies in the U.S. to help them develop a position that contributes positively to the energy and sustainability challenges confronting our planet.
The NSF Center for Chemical Innovation in Solar Fuels (CCI Solar Fuels) focuses on one of the "holygrails" of 21st Century chemistry – the efficient and economical conversion of solar energy into stored chemical fuel. CCI Solar Fuels is targeting the critical science underpinning the solar-driven decomposition of water into H2 and O2. The research is inherently interdisciplinary and collaborative, involving inorganic and organic synthesis, solid-state chemistry and physics, electrochemistry, chemical kinetics and mechanism, and theoretical and computational chemistry. Solar fuels production involves three basic components: light absorption; charge transport; and multielectron redox catalysis. Research in CCI Solar Fuels is targeting the discovery of new molecules and materials with improved performance in each of these areas and the elucidation of the enabling chemistry required to integrate these components for efficient solar water splitting. Requirements for scalability and economic viability demand that CCI Solar research be directed toward earth-abundant elements. Elucidation and control of fundamental interfacial properties are essential for the seamless integration of semiconductors, catalysts, membranes, liquids, and gases into functional assemblies. Collaborative research efforts in CCI Solar are vigorously pursuing development of new semiconductors with optimum light-absorption and charge-separation properties; discovery of new homogeneous and heterogeneous catalysts that split water into H2 and O2 with maximum rates and minimum overpotentials; nanostructuring of catalytic materials to optimize performance; elucidation of reaction mechanisms to identify catalytic bottlenecks and inform designs for their removal; integration of catalysts and semiconductors to produce functional photoanodes and photocathodes; discovery of ionconductive membrane materials to separate anode and cathode compartments; and construction of photoanode-membrane-photocathode assemblies. CCI Solar Fuels activities directly impact thousands of K-12, undergraduate, and graduate students; postdoctoral scholars and working scientists; and members of the public at large. A vigorous outreach program delivers Juice-from-Juice solar science activity kits to elementary, middle, and high school students. Solar Energy Activity Lab kits are involving high school and undergraduate students in research through a combinatorial search for new solar materials. An Informal Science Education program will bring these activities to new and younger audiences. CCI Solar graduate students and postdoctoral scholars acquire invaluable experience by serving as mentors in these outreach programs. Involving underrepresented groups is a particular point of emphasis in the program: seven of eighteen senior investigators are members of underrepresented groups; two investigators focus exclusively on outreach activities; and two investigators are faculty members at universities with large underrepresented student populations. CCI Solar researchers are delivering the message of clean renewable solar fuels in television, radio, and online programs; public lectures, scientific research conferences; and consultations with local, state, and federal government officials. The technological, environmental, economic, and social benefits of renewable solar fuels cannot be overstated: every human being on Earth would be impacted by the development of sustainable energy resources. CCI Solar researchers are actively engaged to bring this goal to fruition. Phase II of CCI Solar Fuels covered the period 1 August, 2008 through 31 July, 2014. 20 PI and Co-PIs at 16 institutions worked with over 300 undergraduate students, graduate students, postdoctoral associates, staff, and visiting students, and faculty. NSF support has produced 146 journal publications that have been cited 5929 times in 3520 articles. The average number of citations per article is 40.6 and the h-index for these publications is 38. Research has resulted in over 30 invention disclosures, patents, and 1 company. 33 alumni are pursuing independent faculty careers in top universities across the world, 6 are working in government research labs, while 20 are working in the industry.
