Chang, Juyeon and Jung, Duk-Young* Synthesis and Characterization of Mesostructured Vanadium Oxide...
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Chang, Juyeon and Jung, Duk-Young* Synthesis and Characteri zation of Mesostructured Vanadium Oxide Department of Chemistry-BK21, SungKyunKwan University, Suwon 440-746, Korea
Chang, Juyeon and Jung, Duk-Young* Synthesis and Characterization of Mesostructured Vanadium Oxide Department of Chemistry-BK21, SungKyunKwan University,
Chang, Juyeon and Jung, Duk-Young* Synthesis and
Characterization of Mesostructured Vanadium Oxide Department of
Chemistry-BK21, SungKyunKwan University, Suwon 440-746, Korea
Slide 2
SKKU Inorganic Materials Lab. Contents 1.Introduction :
Mesoporous Materials 2. Synthesis of Vanadate/Surfactant Clusters.
3. Hydrothermal reaction of Vanadate/Surfactant Clusters. : 1) As
temperature is varied 2) As pH is varied 4.Effect on UV/O 3
Treatment :As time is varied 5. Conclusion
Slide 3
SKKU Inorganic Materials Lab. Introduction Microporous
Mesoporous Macroporous Pore size / 510501005001000 J. S. Beck et
al., J. Am. Chem. Soc. 1992, 114, 10834. Based on
Surfactant-Assisted Ordering C. T. Kresge et al., Nature, 1992,
359, 710. surfactant micelle micellar rod hexagonal array silicate
calcination MCM-41
Slide 4
SKKU Inorganic Materials Lab. Vanadate Solution Speciation
Solution 51 V NMR spectra of vanadate solutions with various pH.
Predominance diagram for V(V)-OH- species V. Luca et al., Chem.
Mater. 1992, 9, 2731. 1 3 5
Slide 5
SKKU Inorganic Materials Lab. Procedure I 1. VO x n- (pH, conc.
control) : 0.15M NaVO 3 solution(pH8.2(1), 6.7(3) and 5.0(5)) with
addition of 2M HCl soln. 2. VO x n- + C 16 TMA-Bromide : Addition
of excess CH 3 (CH 2 ) 15 N(CH 3 ) 3 Br soln.(wt 2.7%) to vanadate
soln 3. The colored precipitates are obtained. : C 16 TMA-V1(white,
pH8.4), C 16 TAM-V3(pale- yellow, pH6.5) and C 16 TMA-V5(orange,
pH4.8) filtered, washing with double distilled water. - C 16
TMA-Bromide (cetyltrimethylammonium bromide ) -
SKKU Inorganic Materials Lab. Kanemite Transformation A.
Monnier et al., Science. 1993, 261, 1299. Hydrothermal
Reaction
Slide 8
SKKU Inorganic Materials Lab. Procedure II 1.Hydrothermal
Reaction at Various Temperatures. : Starting material : C 16
TMA-V1, C 16 TA-V3 and C 16 TMA-V5. Solvent : double distilled
water. Temperature : 403K, 433K, and 463K 2.Hydrothermal Reaction
after pH control. : Starting material : C 16 TMA-V1, C 16 TA-V3 and
C 16 TMA-V5. Solvent : double distilled water. Temperature :
433K
Slide 9
SKKU Inorganic Materials Lab. At Various Temperatures I Powder
XRD Patterns for C 16 TMA- V1 Powder XRD Patterns for C 16 TMA- V5
L : lamellar, H : hexagonal structure
Slide 10
SKKU Inorganic Materials Lab. At Various Temperatures II Powder
XRD Patterns for C 16 TMA-V3 Index d() 100 51.4 110 29.6 200 26.7
300 17.4
Slide 11
SKKU Inorganic Materials Lab. Calcination Thermogravimetric
analysis for hexagonal structure Powder XRD Patterns for hexagonal
structure
Slide 12
SKKU Inorganic Materials Lab. After pH control I Powder XRD
Patterns for C 16 TMA- V1 Powder XRD Patterns for C 16 TMA-V3
Slide 13
SKKU Inorganic Materials Lab. After pH control II Powder XRD
Patterns for C 16 TMA-V5 Index d() 111 44.6 200 38.6 211 31.6 220
27.4 221 25.8 311 23.4 222 22.2 C : cubic structure
Slide 14
SKKU Inorganic Materials Lab. After pH control III 50 nm Powder
XRD Patterns for C 16 TMA-V3 TEM image for the sample at 463K The C
16 TMA-V3 in ethanol and the pH 2.2 with HCl Resulting brown
product was filtered. Hydrothermal reaction at 463K.
Slide 15
SKKU Inorganic Materials Lab. Effect on UV/O 3 Application
Using UV/O 3 lamp (electrical power 20W, UV power 5W at 254 and
180nm). Powder XRD Patterns for UV/O 3 treated sample FT-IR spectra
for UV/O 3 treated sample
Slide 16
SKKU Inorganic Materials Lab. Conclusion I The resulting
composites had lamellar structures and displayed mesophase
transformation to hexagonal and cubic structures after hydrothermal
treatment of vanadate-surfactant composite powders. However, they
are thermally unstable. UV/ozone treatment provides an efficient
means for the condensation of vanadate clusters, but not efficient
for removing of organic surfactant. II It is speculated that the
results are due to the poor condensation of vandates or the strong
interaction between the inorganic framework and the organic
template.