title: Templated assembly of photoswitches significantly increases the energy-storage capacity of solar thermal fuels.
abstract: Large-scale utilization of solar-energy resources will require considerable advances in energy-storage technologies to meet ever-increasing global energy demands. Other than liquid fuels, existing energy-storage materials do not provide the requisite combination of high energy density, high stability, easy handling, transportability and low cost. New hybrid solar thermal fuels, composed of photoswitchable molecules on rigid, low-mass nanostructures, transcend the physical limitations of molecular solar thermal fuels by introducing local sterically constrained environments in which interactions between chromophores can be tuned. We demonstrate this principle of a hybrid solar thermal fuel using azobenzene-functionalized carbon nanotubes. We show that, on composite bundling, the amount of energy stored per azobenzene more than doubles from 58 to 120 kJ mol(-1), and the material also maintains robust cyclability and stability. Our results demonstrate that solar thermal fuels composed of molecule-nanostructure hybrids can exhibit significantly enhanced energy-storage capabilities through the generation of template-enforced steric strain.
authors.affiliation: 1] Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA [2] Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Timothy J
authors.identifier: 000000017235974X
authors.initials: TJ
authors.lastname: Kucharski
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Nicola
authors.initials: N
authors.lastname: Ferralis
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Alexie M
authors.initials: AM
authors.lastname: Kolpak
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Jennie O
authors.initials: JO
authors.lastname: Zheng
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Nocera
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Grossman
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D011211:Electric Power Supplies; D037742:Nanotubes, Carbon / Q000737:chemistry; D055668:Photochemical Processes; D012993:Solar Energy; D013816:Thermodynamics
chemical_list: D001391:Azo Compounds; D037742:Nanotubes, Carbon; C009850:azobenzene
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