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.

Thanks