Li Yanping 20130728
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Transcript of Li Yanping 20130728
Li Yanping20130728
讨论制备方法对光催化剂CuO/TiO2活性的影响
Recent experimental summary
Other researchers’ reports
Other researchers’ reports
1.Fabrication and comparison of highly efficient Cu incorporated TiO2 photocatalyst for hydrogen generation from water
Efficient Cu incorporated TiO2 photocatalysts for hydrogen generation were fabricated by four methods: in situ sol-gel, wet impregnation, chemical reduction of Cu salt, and in situ photo-deposition.
Characteristics:
different chemical states of Cu
different distribution ratio of Cu between surface and bulk phases of the photocatalyst
the Cu content in the photocatalyst play a significant role in hydrogen generation
Conclusion:situ sol-gel method exhibited the highest stability
It was discovered that the fabrication methods determined: the chemical state of Cu,
distribution ratio of Cu within the photocatalyst, BET surface area of thecatalyst,
crystal structure of the TiO2support.
2. Wu and Lee reported that Cu doping within the TiO2
lattice had a negative effect on photocatalytic hydrogen generation as opposed to Cu deposition.
Wu NL, Lee MS. Enhanced TiO2photocatalysis by Cu in hydrogen production from aqueous methanol solution. Int J Hydrog Energy 2004;29:1601-5.
3. Boccuzzi et al. compared properties and activity ofCu-TiO2 prepared by wet impregnation and chemisorption hydrolysis methods, and found that samples with the samechemical composition exhibited a marked difference of up to 100 times in the hydrogenation of 1,3-cyclooctadiene.
Boccuzzi F, Chiorino A, Gargano M, Ravasio N. Preparation,characterization, and activity of Cu/TiO2catalysts. 2. Effect of the catalyst morphology on the hydrogenation of 1,3-cyclooctadiene and the CO-NO reaction on Cu/TiO2 catalysts. J Catal 1997;165:140-9.
Boccuzzi F, Chiorino A, Martra G, Gargano M, Ravasio N,Carrozzini B. Preparation, characterization, and activity of Cu/TiO2catalysts. 1. Influence of the preparation method onthe dispersion of copper in Cu/TiO2. J Catal 1997;165:129-39.
Recent experimental summary
1.Different preparation methods of CuO/TiO2catalysts
1.1 The activity of catalyst
3155.72667
2353.47316
1996.899771827.82203 1821.91958
1280.63688
355.77204
Chemical adsorption Composite precipitation Ethanol immersion Simple wet impregnation Second impregnation Sol-gel Pure P25
0
500
1000
1500
2000
2500
3000
Hyd
roge
n P
rodu
ctio
n ra
te (μ
mol
/(g.h
))
different methods of CuO-TiO2 photocatalyst (15)
0 2 4 6 8 10 12 14 160
500
1000
1500
2000
2500
3000
Hyd
roge
n P
rodu
ctio
n ra
te (μ
mol
/(g.h
))
Time (h)
Chemical adsorption2674.44
1460.30
1.2The stability of the catalystsThe stability of the chemical adsorption
54.6%
Ethanol immersion
0 2 4 6 8 10 12 14 16 180
200
400
600
800
1000
1200
1400
1600
1800
2000H
ydro
gen
Pro
duct
ion
rate
(μm
ol/(g
.h))
Time (h)
1609.41
1125.29
69.9%
The stability of the ethanol impregnation
0 2 4 6 8 10 12 14 16 18-0.50
-0.45
-0.40
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
activ
ity d
eclin
e (%
)
Time (h)
Chemical adsorption
0 2 4 6 8 10 12 14 16 18-0.50
-0.45
-0.40
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
activ
ity d
eclin
e (%
)
Time (h)
Ethanol immersion
-0.45
-0.3
Activity decline: x-initial initial
活性 1.34倍,下降 1.5倍
0 200 400 600 800 1000
0.01
0.00
-0.01
-0.02
-0.03
-0.04
Con
sum
ptio
n of
H2
(a.u
.)
temperature ( )℃
Ethanol impregnation
0 200 400 600 800 10000.01
0.00
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
Con
sum
ptio
n of
H2
(a.u
.)
temperature ( )℃
chemical adsorption decomposition
H2-TPR
1.3BET data of the catalystsPore distribution of the catalyst
1 10 100-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
dV/dD (c
m3/(g
.nm))
Pore Diameter (nm)
simple wet impregnation
1 10 100
0.000
0.002
0.004
0.006
0.008
0.010
dV/dD (c
m3/(g
.nm))
Pore Diameter (nm)
Second impregnation
1 10 100
0.000
0.001
0.002
0.003
0.004
0.005
0.006
dV/dD (c
m3/(g
.nm))
Pore Diameter (nm)
Ethanol impregnation
26nm 2nm,31nm
1 10 100
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
dV/dD (c
m3/(g
.nm))
Pore Diameter (nm)
Composite precipitation
1 10 100
0.00
0.02
0.04
0.06
0.08
0.10
0.12
dV/dD (cm
3/(g
.nm))
Pore Diameter (nm)
sol-gel
1 10 100
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
dV/dD (c
m3/(g
.nm))
Pore Diameter (nm)
chemical adsorption
3.9nm
3nm,33nm
2% CuO/TiO2 SBET
(m2/g)Pore
diameter(nm)
Pore volume(cm3/g)
Chemical adsorption
46.8 29.0 0.326Composite deposition
47.2 33.3 0.372Ethanol
impregnation46.9 31.8 0.370
Sol-gel 92.0 3.9 0.137Simple wet
impregnation45.6 26.3 0.344
Second impregnation
44.9 25.9 0.322
Specific surface area,pore diameter and pore volume of the catalysts
0.0 0.2 0.4 0.6 0.8 1.0
0
50
100
150
200
250
Vol
une
Ads
orbe
d (c
m3 S
TP/g
)
Relative Pressure (P/PO)
chemical adsorption
0.0 0.2 0.4 0.6 0.8 1.0
10
20
30
40
50
60
70
80
90
Vol
une
Ads
orbe
d (c
m3 S
TP/g
)
Relative Pressure (P/PO)
sol-gel
N2 adsorption stripping curve
H2-TPR
0 200 400 600 800 1000
0.01
0.00
-0.01
-0.02
-0.03
-0.04
Con
sumption of H2 (a.u.)
temperature ( )℃
simple wet impregnation
0 200 400 600 800
0.000
-0.005
-0.010
-0.015
-0.020
-0.025
-0.030
Consumption of H2 (a.u.)
temperature ( )℃
second impregnation
0 200 400 600 800 1000
0.01
0.00
-0.01
-0.02
-0.03
-0.04
Con
sumption of H
2 (a.u.)
temperature ( )℃
Ethanol impregnation
0 200 400 600 800 1000
0.02
0.00
-0.02
-0.04
-0.06
-0.08
-0.10
-0.12
Consumption of H2 (a.u.)
temperature ( )℃
composite precipitation
0 200 400 600 800 10000.005
0.000
-0.005
-0.010
-0.015
-0.020
-0.025
Con
sumption of H2 (a.u.)
temperature ( )℃
sol-gel
0 200 400 600 800 10000.01
0.00
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
Con
sumption of H2 (a.u.)
temperature ( )℃
chemical adsorption decomposition
200 300 400 500 600 700 800-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Abs
orbe
nce
(a.u
.)
Wavalength (nm)
P25 simple wet impregnation second impregnation ethanol impregnation composite precipitation chemical adsorption sol-gel
Uv-vis
Plasmonic photocatalysis(Ag/SiO2core –shell, TiO2)Reason:TiO2,3.2eV, near UV irradiation can excite pairs of electrons and holes Ag NPs , a very intense LSP absorption band in the near-UV a considerable enhancement of the electric near-field in the vicinity of the Ag NPsenhanced near-field could boost the excitation of electron –hole pairsBut, Ag NPs, would be oxidized at direct contactwith TiO2
A Plasmonic Photocatalyst Consisting of Silver Nanoparticles Embedded in Titanium Dioxide
To prevent this oxidation, Ag NPs have to be coated with a passive material, such as SiO2, to separate them from TiO2.
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