TOPOTACTIC SOLIDSTATE SYNTHESIS METHODS: HOSTGUEST INCLUSION CHEMISTRY

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TOPOTACTIC SOLID-STATE SYNTHESIS METHODS
HOST-GUEST INCLUSION CHEMISTRY

• Ion-exchange, injection, intercalation type
  synthesis
• Ways of modifying existing solid state structures
  while maintaining the integrity of the overall
  structure
• Precursor structure
• Open structure or porous framework
• Ready diffusion of guest atoms, ions, organic
  molecules, polymers, organometallics,
  coordination compounds, nanoclusters,
  bio(macro)molecules into and out of the
  structure/crystals

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TOPOTAXY HOST-GUEST INCLUSION
1D- Tunnel Structures
2D- Layered Structures
-TiO2 -hWO3 -TiS3
3D-Frameworks
-Graphite -TiS2 -TiO2(B) -KxMnO2 -FeOCl -HxMoO3 -b
alumina -LixCoO2
Pivotal topotactic materials properties for
functional utility in Li solid state battery
electodes, electrochromic mirrors and windows,
fuel and solar cell electrolytes and electrodes,
chemical sensors, superconductors
-zeolites -LiMn2O4 -cWO3
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TOPOTACTIC SOLID-STATE SYNTHESIS METHODS
HOST-GUEST INCLUSION CHEMISTRY

• Penetration into interlamellar spaces 2-D
  intercalation
• Into 1-D channel voids 1-D injection
• Into cavity spaces 3-D injection
• Classic materials for this kind of topotactic
  chemistry
• Zeolites, TiO2, WO3 channels, cavities
• Graphite, TiS2, NbSe2, MoO3 interlayer spaces
• Beta alumina interlayer spaces, conduction
  planes
• Polyacetylene, NbSe3 inter chain channel spaces

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TOPOTACTIC SOLID-STATE SYNTHESIS METHODS
HOST-GUEST INCLUSION CHEMISTRY

• Ion exchange, ion-electron injection, atom,
  molecule intercalation and occlusion, achievable
  by non-aqueous, aqueous, gas phase, melt
  techniques
• Chemical, electrochemical synthesis methods
• This type of topotactic solid state chemistry
  creates new materials with novel properties,
  useful functions and wide ranging applications
  and myriad technologies

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GRAPHITE
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GRAPHITE INTERCALATION COMPOUNDS
4x1/4 K 1
8x1 C 8
C8K stoichiometry
G (s) K (melt or vapor) C8K (bronze) C8K
(vacuum, heat) C24K C36K C48K
C60K Staging, distinct phases, ordered guests, K
? G CT AAAA sheet stacking sequence K nesting
between parallel eclipsed hexagons, Typical of
many graphite H-G inclusion compounds
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GRAPHITE INTERCALATION ELECTRON DONORS AND
ACCEPTORS
SALCAOs of the p-pi-type create the p valence and
p conduction bands of graphite, very small band
gap, essentially metallic conductivity, single
crystal properties in-plane 104 times that of
out-of plane conductivity - thermal, electrical
properties tuned by degree of CB band filling or
VB emptying
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INTERCALATION REACTIONS OF GRAPHITEOxidative,
Reductive or Charge Neutral?

• G (HF/F2/25oC) ? C3.3F to C40F (white)
• intercalation via HF2- not F- - relative size,
  charge, ion, dipole, polarizability effects -
  less strongly interacting - more facile diffusion
• G (HF/F2/450oC) ? CF0.68 to CF (white)
• G (H2SO4 conc.) ? C24(HSO4).2H2SO4 H2
• G (FeCl3 vapor) ? CnFeCl3
• G (Br2 vapor) ? C8Br

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PROPERTIES OF INTERCALATED GRAPHITE

• Structural planarity of layers often unaffected
  by intercalation - bending of layers has been
  observed - intercalation often reversible
• Modification of thermal and electrical
  conductivity behavior by tuning degree of p-CB
  filling or p-VB emptying
• Anisotropic properties of graphite intercalation
  systems usually observed
• Layer spacing varies with nature of the guest and
  loading
• CF 6.6 Å, C4F 5.5 Å, C8F 5.4 Å

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BUTTON CELLS LITHIUM-GRAPHITE FLUORIDE BATTERY
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BUTTON CELLSLITHIUM-GRAPHITE FLUORIDE BATTERY

• Cell electrochemistry
• xLi CFx ? xLiF C
• xLi ? xLi e-
• CxxF- xLi xe- ? C xLiF Nominal cell
  voltage 2.7 V
• CFx safe storage of fluorine, intercalation of
  graphite by fluorine
• Millions of batteries sold yearly, first
  commercial Li battery, Panasonic
• Lightweight high energy density battery - cell
  requires stainless steel electrode/lithium metal
  anode/Li-PEO fast ion conductor/CFx intercalate
  - acetylene black electrical conductor
  poly(vinylidenedifluoride) mechanical support
  cathode/aluminum charge collector electrode

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C60-G INTERCALATING BUCKBALL INTO GRAPHITE NEW
HYDROGEN STORAGE MATERIAL

• Thermally induced 600oC intercalation of C60 into
  G
• Hexagonal close packed C60 between graphene
  sheets
• Sieves H2 from larger N2
• Physisorbed H2 in intralayer void spaces
• Rapid adsorption-desorption
• Dead capacity because of volume occupied by C60
• Capacity possibly enhanced by reducing filling
  fraction of C60

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SYNTHESIS OF BORON AND NITROGEN GRAPHITES -
INTRALAYER DOPING

• New ways of modifying the properties of graphite
• Instead of tuning the degree of CB/VB filling
  with electrons and holes using the traditional
  methods focus on interlayer doping
• Put B or N into the graphite layers, deficient
  and rich in carriers, enables intralayer doping
  with holes (VB) and electrons (CB) respectively
• Also provides a new intercalation chemistry

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SYNTHESIS OF AND BC3THEN PROVING IT IS SINGLE
PHASE?

• Traditional heat and beat
• xB yC (2350oC) ? BCx
• Maximum 2.35 at B incorporation in C
• Poor quality not well-defined materials
• New approach, soft chemistry, low T, flow
  reaction, quartz tube
• 2BCl3 C6H6 (800oC) ? 2BC3 (lustrous film on
  walls) 6HCl

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CHEMICAL AND PHYSICAL CHARACTERIZATION OF BC3

• BC3 15/2F2 ? BF3 3CF4
• Fluorine burn technique
• BF3 CF4 1 3
• Shows BC3 composition no evidence of precursors
  or intermediates
• Electron and Powder X-Ray Diffraction Analysis
• Shows graphite like interlayer reflections (00l)

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CHEMICAL AND PHYSICAL CHARACTERIZATION OF BC3

• 2BC3 (polycryst) 3Cl2 (300oC) ? 6C (amorph)
  2BCl3
• C (cryst graphite) Cl2 (300oC) ? C (cryst
  graphite)
• This neat experiment proves B is truly a
  "chemical" constituent of the graphite sheet and
  not an amorphous component of a "physical"
  mixture with graphite
• Synthesis, analysis, structural findings all
  indicate a graphite like structure for BC3 with
  an ordered B, C arrangement in the layers

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STRUCTURE OF BORON GRAPHITE BC3Rietfeld PXRD
Structure Refinement
4Cx1/4 2Cx1/2 10Cx1 12C
6Bx1/2 1Bx1 4B
Probable layer atomic arrangement with
stoichiometry BC3
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CHEMICAL AND PHYSICAL CHARACTERIZATION OF BC3

• BC3 interlayer spacing similar to graphite
• Also similar to graphite like BN made from
  thermolysis of inorganic benzene - borazine
  B3N3H6 - thinking outside of the box - F doping
  by using fluorinated borazine!!!
• Four probe basal plane resistivity on BC3 flakes
• s(BC3)AB 1.1 s(G)AB, (greater than 2 x 104
  ohm-1cm-1)
• Implies B effect is not the unfilling of VB to
  give a metal but rather the creation of localized
  states in electronic band gap making boron
  graphite behave like a substitutionlly doped
  graphite maybe with a larger band gap recall BN
  is a wide band gap insulator!!!

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4-PROBE CONDUCTIVITY MEASUREMENTS
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REPRESENTATIVE BC3 INTERCALATION CHEMISTRY

• BC3 S2O6F2 ? (BC3)2SO3F Oxidative
  Intercalation
• Note O2FSO--OSO2F, peroxydisulfuryl fluoride
  strong oxidizing agent, weak peroxy-linkage
  easily reductively cleaved to stable
  fluorosulfonate anion 2SO3F-
• (BC3)2SO3F Ic 8.1 Å, (C7)SO3F Ic
  7.73 Å, (BN)3SO3F Ic 8.06 Å
• BC3 Ic 3-4 Å , C
  Ic 3.35 Å, BN Ic 3.33 Å
• More Juicy Redox Intercalation Chemistry for BC3
• BC3 NaNaphthalide-/THF ? (BC3)xNa (bronze,
  first stage, Ic 4.3 Å)
• BC3 Br2(l) ? (BC3)15/4Br (deep blue)

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ATTEMPT TO INCORPORATE NITROGEN INTO THE GRAPHITE
SHEETS, EVIDENCE FOR C5N

• Pyridine Cl2 (800oC, flow, quartz tube) ?
  silvery deposit (PXRD Ic 3.42 Å)
• Fluorine burning of silver deposit ? CF4/NF3/N2
• No signs of HF, ClF1,3,5 in F2 burning reaction
• Superior conductivity wrt graphite?
• Try to balance the fluorine burning reaction to
  give the nitrogen graphite stoichiometry of C5N -
  a challenge for your senses!!! 4C5N 43F2 ?
  20CF4 2NF3 N2

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Soft Synthesis of Single-Crystal Silicon
Monolayer SheetsIntercalation Facilitated
Exfoliation
Structural model of CaSi2
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SYNTHESIS OF SILICON NANOSHEETS

• Chemical exfoliation of calcium disilicide, CaSi2
• CaSi2 synthesized from stoichiometric amounts
  CaSi, Si, Mg, Cu crucible, RF heating, Ar
  atmosphere, cool to RT, product plate-like
  crystals
• Hexagonal layered structure (a) consisting of
  alternating Ca layers and corrugated Si (111)
  planes in which the Si6 rings are interconnected
• To exfoliate precursor-layered crystals into
  their elementary layers must adjust the charge on
  the Si layer.
• Because CaSi2 is ionic (i.e. Ca2(Si)2) the
  electrostatic interaction between the Ca2 and Si
  layers is strong so key is to reduce charge on
  the negatively charged silicon layers.

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SYNTHESIS OF SILICON NANOSHEETS

• Mg-doped CaSi2 prepared CaSi1.85Mg0.15 in which
  Mg was doped by ion exchange into the CaSi2 or
  direct synthesis
• Si monolayer sheets (b, c) prepared through
  chemical exfoliation of CaSi1.85Mg0.15 by
  immersion in a solution of propylamine
  hydrochloride (PAHCl),
• Ca(2) ions are de-intercalated and converted
  into a dispersion of silicon sheets charge
  balanced by PAH()
• The composition of monolayer silicon sheets was
  determined by XPS to be SiMgO7.01.37.5,
  structure by XRD, ED, TEM, AFM

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CHARACTERIZATION OF SILICON NANOSHEETS TEM, ED,
XRD, AFM
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OPTICAL PROPERTIES OF SILICON NANOSHEETS

• RT optical properties of Si nanosheets
• UV/Vis spectra of suspensions of Si Nanosheets at
  various concentrations. Inset the absorbance at
  268 nm is plotted against concentration of
  sheets.
• PL spectra of Si Nanosheets dispersed in water
  with an excitation wavelength of 350 nm
  (indicated by an arrow).

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INTERCALATION SYNTHESIS OF TRANSITION METAL
DICHALCOGENIDES

• Group IV, V, VI MS2 and MSe2 Compounds
• Layered structures
• Most studied is TiS2
• hcp S2-
• Ti4 in Oh sites
• Van der Waals gap

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INTERCALATION SYNTHESIS OF TRANSITION METAL
DICHALCOGENIDES

• Li intercalated between the layers
• Li resides in well-defined Td S4 interlayer
  sites
• Electrons injected into Ti4 t2g CB states
• LixTiS2 with tunable band filling and unfilling
• Localized xTi(III)-(1-x) Ti(IV) vs delocalized
  Ti(IV-x) electronic bonding models???
• VDW gap prized apart by 10

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SEEING INTERCALATION - DIRECT VISUALIZATION
OPTICAL MICROSCOPY
Intercalating lithium - see the layers spread
apart
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ELECTROCHEMICAL SYNTHESIS OF LixTiS2 TiS2
xLi xe- ? LixTiS2 AN ATTRACTIVE ENERGY
STORAGE SYSTEM???
2.5V open circuit (EF(Li)-EF(TiS2) - no current
drawn - energy density 4 x Pb/H2SO4 battery of
same weight
Controlled potential coulometry, voltage
controlled Li intercalation where x is number of
equivalents of charge passed
Li metal anode Li ? Li e-
PEO/Li(CF3SO3) polymer-salt electrolyte or
propylene carbonate/LiClO4 non aqueous electrolyte
PVDF(filler)/C(conductor)/TiS2/Pt(contact)
composite cathode TiS2 xLi xe- ? LixTiS2
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CHEMICAL SYNTHESIS OF LixTiS2

• xC4H9Li TiS2 (hexane, N2/RT) ? LixTiS2
  x/2C8H18
• Filter, hexane wash
• 0 ? x ? 1
• Electronic description LixTix(III)Ti(1-x) (IV)S2
  mixed valence localized t2g states (hopping
  semiconductor - Day and Robin Class II) or LixTi
  (IV-x)S2 delocalized partially filled t2g band
  (metal - Day and Robin Class III)

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Li/TiS2 AN ATTRACTIVE ENERGY SOURCE BUT MANY
TECHNICAL OBSTACLES TO OVERCOME

• Technical problems need to be overcome with both
  the Li anode, intercalation cathode and
  polymer-salt electrolyte
• Battery cycling causes Li dendritic growth at
  anode - need other Li-based anode materials, Li-C
  composites, Li-Sn, Li-Si alloys - also rocking
  chair LixMO2 configuration
• Mechanical deterioration at the cathode due to
  multiple intercalation-deintercalation lattice
  expansion-contraction cycles
• Cause lifetime, corrosion, reactivity, and kaboom
  safety hazards

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OTHER INTERCALATION SYNTHESES WITH TiS2

• Cu, Ag, H, NH3, RNH2, Cp2Co, chemical,
  electrochemical
• Cobaltacene Cp2Co(II) especially interesting 19e
  guest
• Cp2Co(III)xTix3Ti1-x4S2 chemical-electronic
  description consistent with structure, hopping
  SC, spectroscopy
• Temperature dependent solid state NMR shows two
  forms of Cp ring wizzing (lower T) and molecule
  tumbling dynamics (higher T) with Cp2Co
  molecular axis orthogonal and parallel to layers,
  dynamics yields activation energies for the
  different rotational processes

Synthesis, Cp2Co-CH3CN (solution)-TiS2(s)
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EXPLAINING THE MAXIMUM 3Ti 1Co STOICHIOMETRY IN
(Cp2Co)0.3TiS2
Interleaved Cp2Co() cations Matching trigonal
symmetry of hcp chalcogenide sheet Third of
interlayer space filled Geometrical and steric
requirements of packing transverse oriented
metallocene in VDV gap
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Inhibition of Energy Transfer between Conjugated
Polymer Chains in Host-Guest Nanocomposites
Generates White Photo- and Electroluminescence
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PXRD DIAGNOSTICS

• Chemical structures of blue-emitting PFO,
  green-emitting F8BT, and red-emitting MEH-PPV
• XRD patterns of a restacked SnS2 film (no
  polymer), and a blend-intercalated-SnS2
  nanocomposite film.

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WHITE LIGHT LED DIAGNOSTICS

• PL spectra of separate SnS2/conjugated-polymer-int
  ercalated nanocomposites,
• Blend of only the three polymers (excitation 380
  nm),
• PL (excitation 380 nm) and EL of a
  blend-intercalated/SnS2 nanocomposite film.
• Inset excitation spectra for emission at 580 nm
  of a blend of only the three polymers and the
  blend-intercalated/SnS2 nanocomposite.

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INTERCALATION ZOO

• Channel, layer and framework materials
• 1-D chains TiO2 channels, (TiS3
  Ti(IV)S(2-)S2(2-), NbSe3 Nb(IV)Se(2-)Se2(2-)),
  contain disulfide and diselenide units in Oh
  building blocks to form chain
• 2-D layers MS2, MSe2, NiPS3 Ni2(P2S6), ABA CdI2
  type packing, alternating layers of octahedral
  NiS6 and trigonal P2S6 groupings with SS Van der
  Waals gap, FeOCl, V2O5.nH2O, MoO3, TiO2 (layered
  polymorph B see Chimie Douce later)
• 3D framework zeolites, WO3, Mo6S8, Mo6Se8
  (Chevrel phases)

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FACE BRIDGING OCTAHEDRAL TITANIUM TRISULFIDE AND
NIOBIUM TRISELENIDE BUILDING BLOCKS FORM 1-D
CHAINS
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3-D OPEN FRAMEWORK TUNGSTEN OXIDE AND TUNGSTEN
OXIDE BRONZES MxWO3
c-WO3 c-ReO3 structure type with injected
cation M(q) center of cube and charge balancing
qe- in CB, MxWO3 Perovskite structure type M(q)
O CN 12, O(2-) W CN 2, W(VI) O CN 6
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Unique 2-D layered structure of MoO3 Chains of
corner sharing octahedral building blocks sharing
edges with two similar chains, Creates
corrugated MoO3 layers, stacked to create
interlayer VDW space, Three crystallographically
distinct oxygen sites, sheet stoichiometry 3x1/3
( ) 2x1/2 ( )1 ( )
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ELECTROCHEMICAL OR CHEMICAL SYNTHESIS OF MxWO3

• xNa xe- WO3 ? NaxWx5W1-x6O3
• xH xe- WO3 ? HxWx5W1-x6O3
• Injection of alkali metal cations generates
  Perovskite structure types
• M oxygen coordination number 12, resides at
  center of cube
• H protonates oxygen framework, exists as MOH
  groups

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SYNTHESIS DETAILS FOR MxMO3 WHERE M Mo, W
AND M INJECTED PROTON OR ALKALI OR ALKALINE
EARTH CATION

• n BuLi/hexane CHEMICAL
• LiI/CH3CN
• Zn/HCl/aqueous
• Na2S2O4 aqueous sodium dithionate
• Pt/H2
• Topotactic ion-exchange of MxMO3 with M cation
  
• Li/LiClO4/MO3 ELECTROCHEMICAL
• Cathodic reduction in aqueous acid electrolyte
• MO3 H2SO4 (0.1M) Û HxMO3

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VPT GROWTH OF LARGE SINGLE CRYSTALS OF MOLYBDENUM
AND TUNGSTEN TRIOXIDE AND CVD GROWTH OF LARGE
AREA THIN FILMS

• VPT CRYSTAL GROWTH
• MO3 2Cl2 (700C) Û (800C) MO2Cl2 Cl2O
• CVD THIN FILM GROWTH
• M(CO)6 9/2O2 (500C) ? MO3 6CO2

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MANY APPLICATIONS OF THIS MxMO3 CHEMISTRY AND
MATERIALS

• Electrochemical devices like chemical sensors, pH
  responsive microelectrochemical chips and
  electrochromic displays, smart windows, advanced
  batteries
• Behave as low dopant mixed valance hopping
  semiconductors
• Behave as high dopant metals
• Electrical and optical properties best understood
  by reference to simple DOS picture of
  MxMx5M1-x6O3

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COLORING MOLYBDENUM TRIOXIDE WITHPROTONS, MAKING
IT ELECTRONICALLY, IONICALLY CONDUCTIVE AND A
SOLID BR?NSTED ACIDElectronic band structure in
HxMoO3 molybdenum oxide bronze, tuning color,
electronic conductivity, acidity with x
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COLOR OF TUNGSTEN BRONZES, MxWO3 INTERVALENCE
W(V) TO W(VI) CHARGE TRANSFER
IVCT
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ELECTRONIC AND COLOR CHANGES BEST UNDERSTOOD BY
REFERENCE TO SIMPLE BAND PICTURE OF
NaxMox5Mo1-x6O3

• SEMICONDUCTOR TO METAL TRANSITION ON DOPING
  MxMoO3
• MoO3 Band gap excitation from O2-(2pp) VB to
  Mo6 (5d) CB, LMCT in UV region, wide band gap
  insulator
• NaxMox5Mo1-x6O3 Low doping level, narrow band
  gap hopping semiconductor, narrow localized Mo5
  (d1) VB, visible absorption, essentially IVCT
  Mo5 to Mo6 absorption, mixed valence hopping
  semiconductor
• NaxMox5Mo1-x6O3 High doping level, partially
  filled valence band, narrow delocalized Mo5 (d1)
  VB, visible absorption, IVCT Mo5 to Mo6 and
  shows metallic reflectivity (optical plasmon) and
  conductivity

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HxMoO3 TOPOTACTIC PROTON INSERTION

• Range of compositions 0 largely unaltered by reaction, four phases
• 0.23
• 0.85
• 1.55
• 2.00 x monoclinic
• Similar lattice parameters by XRD, ND of HxMoO3
  cf MoO3
• MoO3 high resistivity semiconductor
• HxMoO3 insertion material SC to M transition
• HxMoO3 strong Br?nsted acid Mo-O(H)-Mo
• HxMoO3 fast proton conductor
• See what happens when single crystal immersed in
  Zn/HCl/H2O

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HxMoO3 TOPOTACTIC PROTON INSERTION
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PROTON CONDUCTION PATHWAY IN HxMoO3
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PROTON CONDUCTION PATHWAY IN HxMoO3

• Part of a HxMoO3 layer
• Showing initial 1-D proton conduction pathway
• Apical to triply bridging oxygen proton migration
  first
• 1H wide line NMR, PGSE NMR probes of structure
  and diffusion
• Doubly to triply bridging oxygen proton migration
  pathway
• Initial proton mobility along c-axis intralayer
  direction for x 0.3
• Subsequently along b-axis interlayer direction
• Single protonation at x 0.36, double
  protonation x 1.7
• More mobile protons higher loading D(300K)
  10-11 vs 10-9 cm2s-1
• Proton-proton repulsion

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ION EXCHANGE SOLID STATE SYNTHESIS

• Requirements anionic open channel, layer or
  framework structure
• Replacement of some or all of charge balancing
  cations by protons or simple or complex cations
• Classic cation exchangers are zeolites, clays,
  beta-alumina, molybdenum and tungsten oxide
  bronzes

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BETA ALUMINA

• High T synthesis of beta-alumina
• (1x)/2Na2O 5.5Al2O3 ? Na1xAl11O17x/2
• Structural reminders
• Na2O Antifluorite ccp Na, O2- in Td sites
• Al2O3 Corundum hcp O2-, Al3 in 2/3 Oh sites
• Na1xAl11O17x/2 defect Spinel, O2- vacancies in
  conduction plane, controlled by x 0.2, Spinel
  blocks 9Å, bridging oxygen columns, mobile Na
  cations in conduction plane, 2-D fast-ion
  conductor

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Spinel blocks, ccp layers of O(2-) Every 5th.
layer has 3/4 O(2-) vacant, defect spinel 4 ccp
layers have 1/2Oh, 1/8Td Al( 3) cation
sites Blocks cemented by rigid Al-O-Al
spacers Na() mobile in 5th open conduction
plane Centrosymmetric layer sequence in
Na1xAl11O17x/2 (ABCA)B(ACBA)C(ABCA)B(ACBA)
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GETTING BETWEEN THE SHEETS OF THE BETA ALUMINA
FAST SODIUM CATION FAST ION CONDUCTOR LIVING IN
THE FAST LANE
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ION EXCHANGE IN Na1xAl11O17x/2
Thermodynamic and kinetic considerations Mass,
size and charge considerations Lattice energy
controls stability of ion-exchanged
materials Cation diffusion, polarizability
effects control rate of ion-exchange
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MELT ION-EXCHANGE OF CRYSTALS

• Equilibria between beta-alumina and MNO3 and MCl
  melts, 300-350oC
• Extent of exchange depends on time, T, melt
  composition
• Monovalents Li, K, Rb, Ag, Cu, Tl, NH4,
  In, Ga, NO, H3O
• Higher valent cations Ca2, Eu3, Pb2
• Higher T melts required for exhigher valent
  cations, strong cation binding, slower cation
  diffusion, 600-800oC typical

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MELT ION-EXCHANGE OF CRYSTALS

• Charge-balance requirements
• 2Na for 1Ca2, 3Na for 1La3
• Controlled partial exchange by control of melt
  composition
• qNaNO3 (1-q)AgNO3
• Na1x-yAgyAl11O17x/2

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KINETICS AND THERMODYNAMICS OF SOLID STATE ION
EXCHANGE

• Kinetics of Ion-Exchange
• Controlled by ionic mobility of the cation
• Mass, charge, radius, temperature, solvent, solid
  state structural properties
• Thermodynamics, Extent of Ion-Exchange
• Ion-exchange equilibrium for cations
• Binding activities between melt and crystal
  phases
• Site preferences
• Binding energetics, lattice energies
• Charge radius ratios

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