"At the root of the opportunities provided by nanoscience to impact our energy security is the fact that all the elementary steps of energy conversion...take place on the nanoscale." - Report of the National Nanotechnology Initiative Workshop on Nanoscience Research for Energy Needs
Nanoscience research has the potential to make major contributions to many areas of basic energy sciences. At the August 5-6 meeting of the Basic Energy Sciences Advisory Committee (see http://www.aip.org/fyi/2004/115.html), Altaf Carim of DOE's Office of Basic Energy Sciences discussed the report of a spring 2004 workshop exploring this topic. The report lays out nine specific research targets for which nanoscience is expected to have a major impact, and six underlying cross-cutting themes for R&D emphasis.
The Nanoscience Research for Energy Needs workshop, held March 16-18, was sponsored by DOE's Office of Basic Energy Sciences and the National Science and Technology Council's Subcommittee on Nanoscale Science, Engineering and Technology. It was one of a number of "Grand Challenge" workshops intended to provide input from the research community to the development of an updated strategic plan for the multi-agency National Nanotechnology Initiative (NNI). According to the report, "The goal of this workshop was to define opportunities and goals in energy-related research for the next decade and to determine the special opportunities that the field of nanoscience affords to energy research."
The report continues, "At the root of the opportunities provided by nanoscience to impact our energy security is the fact that all the elementary steps of energy conversion (charge transfer, molecular rearrangement, chemical reactions, etc.) take place on the nanoscale. Thus, the development of new nanoscale materials, as well as the methods to characterize, manipulate and assemble them, creates an entirely new paradigm for developing new and revolutionary energy technologies. Our workshop has identified nine key areas of energy technology in which nanoscience can have the greatest impact."
These nine research targets are: Scalable methods to split water with sunlight for hydrogen production; Highly selective catalysts for clean and energy-efficient manufacturing; Harvesting of solar energy with 20 percent power efficiency and 100 times lower cost; Solid-state lighting at 50 percent of the present power consumption; Super-strong light-weight materials to improve efficiency of cars, airplanes, etc.; Reversible hydrogen storage materials operating at ambient temperatures; Power transmission lines capable of 1 gigawatt transmission; Low-cost fuel cells, batteries, thermoelectrics, and ultra-capacitors built from nanostructured materials; and Materials synthesis and energy harvesting based on the efficient and selective mechanisms of biology.
"The strategy for achieving these targets," the report says, "lies in growing the R&D efforts in six crosscutting themes." Most of the report is devoted to explaining these six themes, describing such issues as research directions, major technical challenges, implementation strategies and infrastructure needs. The six themes, with selected quotations from the report, follow:
Catalysis by Nanoscale Materials: "Catalysis provides the means of controlling the rates at which chemical bonds are formed and broken," the report says. "The research challenge in nanoscience for catalysis is learning to tune the energy landscape of the chemical reactants as they interact with the nanostructured catalyst materials…. [N]anostructured materials must be designed to match both the structural conformation of the reactants and to control the reaction pathway to the desired product. To accomplish this, new and efficient methods of in-situ characterization and rapid throughput testing of catalytic properties will be required."
Using Interfaces to Manipulate Energy Carriers: "The use of engineered nanostructures at interfaces has demonstrated a compelling potential for improving energy security based on advances in efficient power handling, low-power electronics, energy harvesting, and efficient energy use in lighting. The most significant research challenge needed to address these issues is to create interfaces that are tailored at the nanoscale to optimize transport of energy in many forms (electrons, phonons, photons, excitons)."
Linking Structure and Function at the Nanoscale: "At the heart of nanoscience are the new phenomena and properties that emerge as materials are constructed at the nanometer scale…. The overarching research challenge that we face in designing novel nanomaterials is establishing the physical and chemical principles that determine the functionality that emerges at nanometer length scales, and exploiting this functionality for improved energy security…. Meeting this challenge will involve cross-cutting research correlating exploratory synthesis, functional characterization, and theory, modeling, and simulation."
Assembly and Architecture: "Exploiting the novel properties of individual nanostructures will generally involve assembling the nanostructures into carefully designed and controlled architectures that amplify or modify their desired functionality. The major research challenge is to predict the properties of assemblies of nanostructures and to devise novel strategies for assembly of these architectures, initially in small quantities, but eventually in bulk."
Theory, Modeling, and Simulation for Energy Nanoscience: "Opportunities in nanoscience and technology encompass a combinatorially large range of solid-state and molecular materials, chemical compositions, interface configurations, and system architectures. Predicting the structure, composition, and architectures that give rise to desirable functional behavior is a major research challenge, which can only be met by using the power of theory, modeling, and simulation (TMS)…. Today, the TMS capabilities to meet these needs exist in varying degrees of maturity, with demonstrated potential to develop the expanded power needed for the nanoscience research challenges."
Scalable Synthesis Methods: "The ultimate research challenge is to synthesize functional nanomaterials at a practical manufacturing level in a controllable manner…. The synthesis of nanomaterials involves challenges in the quality, quantity, variety, and integrated design and assembly of nanomaterials."
The 70-page report of the workshop, "Nanoscience Research for Energy Needs," can be found at http://www.sc.doe.gov/bes/reports/files/NREN_rpt.pdf.