Table 1 Catalytic performances of some typical semiconductors

From: Visible light-driven C−H activation and C–C coupling of methanol into ethylene glycol

Catalyst

Formation rate (mmol gcat−1 h−1)

e/h+a

Selectivityb (%)

 

EG

HCHO

HCOOH

CO

CO2

H2

CH4

 

EG

HCHO

HCOOH

UV-Vis light

           

TiO2

0

1.6

0.11

0.16

0.042

2.0

0.053

0.91

0

84

5.6

ZnO

0

3.0

0.038

0.23

0.028

3.1

0.14

0.90

0

91

1.2

g-C3N4

0

0.79

0.33

0.11

0

1.5

0.039

0.92

0

64

27

ZnS

1.3

2.2

0.067

0.083

0

3.4

0.087

0.92

54

43

1.3

Visible light

           

ZnS

0

0

0

0

0

0

0

Cu2O

0

0.46

0

0

0

0.42

0

0.91

0

100

0

Bi2S3

0

0.13

0.017

0.023

0

0.19

0

0.91

0

77

10

CuS

0

0.11

0.013

0

0

0.13

0

1.0

0

89

11

CdS particle

0.28

0.40

0

0

0

0.65

0

0.95

58

42

0

CdS rod

0.46

0.38

0

0

0

0.75

0

0.90

71

29

0

MoS2 sheet/CdSc,d

6.0

2.3

0

0

0

7.5

0

0.91

84

16

0

MoS2 foam/CdSc,d

11

2.5

0

0

0

12

0

0.92

90

10

0

MoS2 sheet

0

0

0

0

0

0

0

MoS2 foam

0

0

0

0

0

0

0

  1. Reaction conditions: solution, 76 wt% CH3OH + 24 wt% H2O, 5.0 cm3; atmosphere, N2; light source, 300-W Xe lamp; UV-Vis light, λ = 320–780 nm; visible light, λ = 420–780 nm
  2. a The ratio of electrons and holes consumed in product formation was calculated by the equation of e/h+ = [2 × n(H2) + 2 × n(CH4)]/[2 × n(EG) + 2 × n(HCHO) + 4 × n(HCOOH) + 4 × n(CO) + 6 × n(CO2)]
  3. b Selectivity was calculated on a molar carbon basis
  4. c CdS without designation denotes the CdS nanorod
  5. d Sheet: MoS2 nanosheet with a content of 5.0 wt%; foam: MoS2 nanofoam with a content of 5.0 wt%