PowerPoint Chang, Juyeon and Jung, Duk-Young*
Synthesis of Mesostructured Vanadium Oxide
Introduction
2. Folding Sheet(FS) Machanism
SKKU Inorganic Materials Lab.
VOxn- (pH, conc. control)
: 0.15M NaVO3 solution(pH8.4, 6.5, 4.8) with addition of 2M HCl soln.
VOxn- + CTA-bromide
The colored precipitates are obtained.
: CTAV1(white, pH8.4), CTAV3(pale- yellow, pH6.5) and CTAV5(orange, pH4.8) filtered, washing with double distilled water.
Hydrothermal treatment with pH control.
: Starting material-CTAV1, CTAV3 and CTAV5, Solvent-double distilled water, pH control with 0.2M HCl soln.
UV/O3 treatment.
: Using UV/O3 lamp (electrical power 20W, UV power 5W at 254 and 180nm)
Procedure
25.3
27.0
26.4
24.9
12.5
27.0
13.4
30.7
25.1
34.8
a
b
c
d
CTAV1
Sample a. dissolved in EtOH & titrated to pH 2.2 with HCl,
Sample from b. synthesized hydrothermally at 120oC
Sample from b. synthesized hydrothermally at 160oC
SKKU Inorganic Materials Lab.
a
b
c
d
23.5
26.4
13.2
24.9
26.4
33.3
13.9
26.9
13.5
26.4
23.5
13.3
12.8
SKKU Inorganic Materials Lab.
a
b
c
d
SKKU Inorganic Materials Lab.
2 Theta (degree)
Hydrothermal treatment(at 180oC) of isolated product by adding HCl from CTAV3 dissolved in EtOH
Small angle X-ray diffraction of Vanadate with different conditions
38.6
31.2
11.1
44.4
(211)
(220)
(321)
a.
b.
b. Hydrothermal treatment(at 170oC) of CTAV3 in water Solution(pH6.7~7.4 with 0.2 NH3 soln.)
SKKU Inorganic Materials Lab.
27.6
b. UV/O3 treatment from sample b.
UV/O3
SKKU Inorganic Materials Lab.
hydrothermal treatment were synthesized.
II. The products have poor thermal stability because of condensation of vanadates or strong interaction between surfactant and vanadates.
According to XRPD and FTIR data, UV/ozone treatment provides an
efficient means for the condensation of vanadate clusters, but not efficient for removing of organic surfactant.
SKKU Inorganic Materials Lab.