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8/13/2019 Alivisatos Presentation
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Nanoscience and the future of the Global Carbon Cycle
In coming decades, problems
of energy and environment will
intensify and science will be
pressed to provide more
options
How can an active new field like
nanoscience be deployed to
help meet these needs of
society?
Paul Alivisatos, LBNL and UC Berkeley, November 2013
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2
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How soon and how deeply must we reduce emissions?
T. F. Stocker, The closing door of climate targets,Science 339280 2013
Peakwarmingcontours
under growthfollowed byreductions
scenarios
t0= 2009C0= 530GtC
E0= 9.3 GtCyr-1r = 1.8% yr-1
= 20C (TtC)-1
1TtC = 1018g C
Tmax= CE(t)={E0er(t-t
0)
E0er(t-t0)e-s(t-t0)t0 < t t1
t > t1
3.2% yr-1starting in
2020
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History and path to reduced carbon intensity.
Courtesy of Don DePaolo, LBNL
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Natural Gas from fracking-Can we use methanemore effcetively?
Abrupt drop in solar costs- How do we store the energy?
Two changes in the energy landscapeare (re-)shaping our opportunities
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Extensive DOE researchstarting in the mid 70s andthrough 80s and 90s, laidthe foundation for the Shale
Gas Revolution
Fluid flow throughnanoporous media,chemistry of nanoscalemineral surfaces will be keyto effective shale gas
utilization
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http://thebreakthrough.org/index.php/voices/michael-shellenberger-and-ted-nordhaus/gas-crushes-coal/
Coal electricity declined by 12.5 percent in
2012, mostly driven by the switch to
natural gas, which increased by almost the
same amount (217 TWh) as coal declined
(216 TWh)
Natural gas is replacing coal in the US
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Mild 2012 winter
Reduced demand for gasoline
Drop in coal-fired electricity generation - historically low natural
gas prices.
US Carbon emissions are actually decreasing
S f f
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Shifting opportunities for catalysis and nanoscience in agas-abundant world
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Today we benefit from solar technologies that followed fromdiscoveries in fundamental science
Quantum MechanicsThermodynamics
Solar Thermal Solar Photovoltaic
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There are oscillations dueto supply/demandimbalances
Solar prices are dropping very fast
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27 GW alreadyinstalled in 2012
65% growth/year,averaged over thelast five years
>100% growth inUS market this year
~$77$bn industry and growinga TWera for solar is in sight
data from Fraunhofer Institute for Solar
Solar deployment is growing dramatically
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Electricity production from solar and wind in Germany in 2012, Compiled by Prof. Bruno Burger,Fraunhofer ISE, October 22, 2012
40% of electricity production from Solar at peakTotal of 190 GWh production that day14% of electricity produced over the 24 hr periodThe Solar Energy Storage Problem
(batteries, artificial photsynthesis)
On May 25, 2012 Germany produced22.4 GWp fromSolar Energy
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$/W
Invent new materials anddiscover concepts
that improve efficiencyto greater than 30%
and that arecompatible with low cost
manufacturing
Invent new processesthat lower thecost of production
of solar modules withpotential efficiencygreater than 30%
-or-
Find a practical way to storetheenergy
As the solar industry grows, there are even moreopportunities for solar energy research
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Organic, Nanocrystal, Quantum
Dot and Nanowire Solar Cells -
as high performancealternatives, and less so for
their low cost
Split the solar spectrum and
harvest three gaps at reasonable
cost
Photonic effects and
manipulation of light
Shifting opportunities for basic research and nanosciencein solar
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Catalysis for methaneuse and CO2 reduction
Energy Storage andArtificial
Photosynthesis
How can nanoscience contribute to
solutions in areas of energy and
environment such as these?
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Scaling Laws
Synthesis and properties of the building blocksThe power of one
The deep biology interconnection
The current era of building...
Themes of nanoscience
relevant to solutions for the Carbon Cycle
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Some SCALING LAWS for nanocrystal properties
Charging energy
Melting temperature
Nanocrystals as Single Structural Domains
Energy level spacing, band gap, artificial atom concept
Control of size, shape, topology, and connectivity on the nanoscale
- new functional materials for energy and environment applications
structure
function
Nanoscience and Energy 101
Scaling law for melting in nanocrystals
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Goldstein, A.N., Echer, C.M. & Alivisatos, A.P. Melting in Semiconductor Nanocrystals. Science256, 14251427 (1992).
Melting study of CdS nanocrystals
e-diffraction vs. T for nanocrystals on aTEM grid
Low melting temperature:
-high quality particles under simple(cheap) conditons- thin films via low T sintering
Scaling law for melting in nanocrystals
- case of colloidal quantum dots
Nanoscience may enable fast and inexpensive synthesis and
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Nanoscience may enable fast and inexpensive synthesis and
manufacturing of high quality materials...
Molecular Beam Epitaxy
of Quantum Structures
Colloidal synthesis
of quantum structures
ResearchSynthesis
IndustrialManufacturing
nascent
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Nanocrystals as Single Structural Domains
Fully reversible structural transformation below 10 nm despite 18% volume change One nucleation event / particle
Large hysteresis compared to bulk (surface rather than defect nucleation)
Simple exponential kinetics
Shape change accompanies transition depends on pathway
Increase in transition pressure in smaller sizes
0.8
0.9
1.0
1.1
Volume(3)
0 2 4 6 8Pressure (GPa)
383 K
Annu Rev Phys Chem46, 595625 (1995).
Science276, 398401 (1997).
simulations by Madden, Dellago, and Rabani...
Batteries and control of nanoscale structural domains
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Batteries and control of nanoscale structural domains
Nanotechnology enabled anodes, cathodes, and transport media
have the potential to revolutionize battery technologies
Balsara
Berkeley
Cui Stanford
Block copolymer electrolytes:dendrite suppression
Nanocrystals or nanowires and
volume change w/Li intercalation
Quantum confinement Artificial atom concept
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Quantum confinement, Artificial atom conceptElectron confinement in a nanocrystal quantum dot
CdSe nanocrystal as quantum dot
E
~1 nm ~4 nm
En =h2n2
8ma2
Alexa 488 Green QDs
QD-565 QD-585
QD-585QD-65520 m
20 m20 m
20 m
Science1998, 281, 2013
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New displays based on quantum dot emission are in development
Color purity, long lifetime, energy savings for mobile
Bandgap (color) variation of semiconductors with size
- The quantum size effect
Q t D t E i i Fil f N
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Quantum Dot Emissive Films from Nanosys
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Polymer
waveguide
Escape cone
High performance PV
(Si, GaAs, etc)
Noah D. Bronstein, Lanfang Li, Yuan Yao, Lu Xu, A. Paul Alivisatos, and Ralph Nuzzo
hn
hn
Luminescent concentration of sunlight
for photovoltaics far from thermodynamic limit
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CdS arm CdSe core
En
ergy
Position
e-
h+
Quantum dot/rods with very large Stokes shift
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0 5 10 15 20
0
1
2
3
4
5
Largest nanorodsPLQY = 70%
Smallest nanorods
PLQY = 70%
Concentration
Aperture Radius (mm)
Fit
Data
35%
Quantum dot/rod luminescent concentrator early results
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Some SCALING LAWS for nanocrystal properties
Charging energy
Melting temperature
Nanocrystals as Single Structural Domains
Energy level spacing, band gap, artificial atom concept
Control of size, shape, topology, and connectivity on the nanoscale
- new functional materials for energy and environment applications
structure
function
Nanoscience and Energy 101
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ClassicalThermodynamic
s
Electro-magneticTheory
QuantumMechanics
What happens when we scale these down tonanometers?
The scientific foundations of todays energy technologies
Nanoscience and Energy 301
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Motors on the nanoscale
Nanoscale Quantum Heat Engineand Chemical Transformations on the
nanoscale
Nanoscale Quantum Thermal Rectifier
How to make switches, grab photons,and push ions on the nanoscale
Nanoscience and Energyfuture prospects
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Nanoscale electromagnetic motor,built with a nanotube rotor, operates
like a conventional motor
A. Zettl
A biological nanoscale motor- new physics
Nature v. 437| p. 916 | 2005
Motors on the nanoscale
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54nm
42nm
Length of 29 DNA:
19, 285 bp ~ 6.5 mPortal motor:connector,prohead RNA,gp16-ATPase
15 Mpa pressure - ~25 Champagne bottles!
DNA packaging motor of Bacteriophage 29
N l b k d ll f d
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Thermodynamics of nanoscale systems are dominated by thermal
fluctuationsMolecular scale machines undergo large fluctuations during theiroperations
Molecular scale machines operate away from thermal equilibrium
Nanoscale motors go backwards as well as forwards
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ClassicalThermodynamic
s
Electro-magneticTheory
QuantumMechanics
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Solar PV
Captures a quantum
of photon energy
Solar Thermal
Thermalizes the energy of light
Photosynthesis
Entropy is reduced
(controlled) by forming
specific chemical bonds
Thermodynamic evolution of solar energy technologies
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Lessons from Nature on SolarLight Harvesting
Graham Fleming
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Li ht h ti i it th FMO tifi
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The FMO complex acts as a rect i f ierfor unidi rect ional energy f lowfrom thelight-harvesting antenna to the reaction center complex by taking advantage ofquantum coherence
and theenergy lands cape
of pigments tuned by the proteiscaffold.
Light harvesting circuitthe FMO rectifier
Artificial photosynthesis
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High density of reactants
(photo-generated charges)leads to more products
10 kBT dissipation required
to ensure directionality ofenergy flow (Crooks!)
Catalysis and flow of
reactants and products must
match solar flux
Is the photosynthetic
reaction center a Quantum
Heat Engine?
Courtesy of Freefoto.com
H
H O
OHH
O OC
OC
O
CH3 O H
CH3
OH
O
OO
O
Artificial photosynthesis
the grand challenge for nanoscience
Elementary chemical and physical transformations of nanocrystals:
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from artificial atoms to functional artificial molecules for energy systems
Addition
These operations can be performed sequentially in anyorder
Nanoscale synthesis now can achieve the complexity of molecular synthesis
Extension andBranching
Cation Exchange
CdXAg2X/CdXCu2X/CdX
Cu+
Cd2+
Ag+
Cd2+
Science, 291, p. 2115 2001
Science, 317 355 2007Science, 306, 1009 2004
Science, 304,p. 711 2004
A nanocrystal stamp collection
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A nanocrystal stamp collection ...
Symmetry, topology, connectivity, directionality
Design these for energy conversions
Design of a photo catalytic unit using the scaling laws
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44
Built in asymmetry
High luminescence quantum yield absent catalysts
Directed flow of electrons and holes to suppress side reactions
Single photocatalyst studies
Beyond hydrogen production to CO2reduction
Quantum confinement control:
Design of a photo-catalytic unit using the scaling laws
h+e-
Holes confinedto seeds,
- directed to an oxidationcatalyst
Electrons squeezed outinto rod- directed to a reduction site
J. Phys. Chem. Lett. 2010, 1, 1051
Photocatalysis model system studied at the single particle level
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y y g p
excess hole left behind in seedquenches luminescence
Coulomb blockade in the Pt- repels electronsdot luminescence increases again
PtCdSe CdS
e-h+h+
hv
PtCdSe CdS
e-h+e-
e-
J. Am. Chem. Soc., 2013, 135 35 , 13049
C t l ti d h i l t f ti
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MOF-74 with three different catalystsbound covalently to its interior to carry outthree different reactions in cascading
fashion Omar Yaghi
Inorganic Micelles
Compartmentalization and sequential catalysis
A
B
C
Catalytic and chemical transformations
Sulfidation of Co nanocrystals-
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y
discovery of the nanoscale Kirkendall effect
Sulfur
Cobalt Hollow Cobalt Sulfide Nanocrystals
180 oC
Y. Yin, R.M. Rioux, C.K. Erdonmez, S. Hughes,G.A. Somorjai, and A.P. Alivisatos, Science2004, 304, 711
Y. Yin, C. Erdonmez, A. Cabot, S. Hughes, A. P. Alivisatos
Advanced Functional Materials 16 (11): 1389-1399 Jul 21 2006
o nanoreac ors or ca a y c
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yapplications
Pt(acac)2Reduction by alkanediol
Pt nanocrystals (seeds)
Co2(CO)8
Pt@Co core-shellnanopartilces
OxygenPt@CoO
180 C
Pt nanocrystals Pt@CoO nanoreactors
5 nm
1) Y. Yin, R.M. Rioux, C.K. Erdonmez, S. Hughes, G.A. Somorjai, and A.P. Alivisatos, Science 2004, 304, 711.2) Y. Yin, C. Erdonmez, A. Cabot, S. Hughes, A. P. Alivisatos, Advanced Functional Materials 16 (11): 1389-1399 Jul
Au@FexOy stable at 100C above normal sintering T
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Au@FexOystable at 100 C above normal sintering T
Au@FexOyAu/TiO2
Au/FexOy
dimer
Before
Catalysis
AfterCatalysis
10 nm10 nm
10 nm10 nm50 nm
50 nm
In the end, the encapsulated catalyst operates with much higher turnov
Catalytic nanoreactorscontrol of reactant and product flow
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y p
Inorganic Micelle
Prevent sintering
Hydrophilic/hydrophobic
microenvironment
Concentrate intermediates
Ci
Hydrophobic tailCatalyst 1
Catalyst 2Reagent A
IntermediateB
Product C
Synthesis of Inorganic Micelles
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y g
S. Guo, J. Gong, P. Jiang, M. Wu, Y. Lu, S. Yu,Adv. Funct. Mater., 2008, 18, 872.
Au@SiO2 inorganic micel
Zhang,
Xing-Zhong Shu,
J. Matthew Lucas,
F. Dean Toste,
Gabor A. Somorjai, A. Paul Alivisatos, 2013 under revie
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Nanoscience and Energy future prospects
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Motors on the nanoscale
Nanoscale Quantum Heat Engineand Chemical Transformations on thenanoscale
Nanoscale Quantum Thermal Rectifier
How to make switches, grab photons,and push ions on the nanoscale
Nanoscience and Energyfuture prospects
N l Ph i U l d i h h i
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Nanoscale Phonon Waveguide
Thermal conductivity unchanged!
radius of curvature (70~200nm)
~ phonon mean free path
Nanoscale Thermal Rectifier
Thermal rectifier in 1D
Nanoscale Phononics: Unexplored, rich physics
Alex Zettl
Phonons on the nanoscale
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variable resistance
fiber optic cable phonon waveguide?waveguide
trimpot tunable thermal link?
rectifier
amplifier transistor
diode thermal rectifier?
thermal amplifier?
Are nanophononic analogs to electronics/optics possible?
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Nanofluidic circuitry: manipulating ion transport
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Field control of ions and biomoleculesArtificial Ion PumpsTrapping, transport, sorting, valves and pumps
source
drain
gate
Microfluidicchannels
Nanofluidic channelInner diameter:
5-50 nm
Nanofluidic circuitry: manipulating ion transport
Arun Majumdar and Peidong Yang
How can nanoscience contribute to
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Catalysis for methaneuse and CO2 reduction
Energy Storage andArtificial
Photosynthesis
How can nanoscience contribute to
solutions in areas of energy and
environment such as these?
Th f i
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Scaling Laws
Synthesis and properties of the building blocks
The power of one
The deep biology interconnection
The current era of building...
Themes of nanoscience
relevant to solutions for the Carbon Cycle
What I cannot create,I do not understand.