1. 1 Recent Progress of Photocatalytic Water Splitting and Preliminary Work Zhibin Lei Supervisor: Prof. Can Li Jan. 13, 2003 State Key laboratory of Catalysis, Dalian Institute of Chemical Physics

2. ☻ Significance of hydrogen energy ☻ Mechanism of photocatalytic water splitting ☻ Recent development of water splitting ☻ My preliminary work and next plan Content

3. 3 The concentration change of CO 2 in air during the past one thousand years Significance of hydrogen energy

4. 4 The funds used for the hydrogen project of USA in the past six years

5. 5 我国未来所需氢的预测结果（万吨） 项 目项 目 201020202050 合成氨 768936.2 炼油厂加氢精制 773.11141.7 燃料电池电动车 326.69678758.4 燃料电池发电 73.2216.71962.8 合 计 1939.13261.612799.1

6. 6 Predict hydrogen source in the next fifty years

7. 每年投射到地面上的太阳能约 1.05×10 18 kWh ， 相当于 1.3×10 6 亿吨标准煤 Energy source Environment Economy Photocatalyst H2OH2O H 2 + ½ O 2 hvhv

8. A.Fijishima and K.Honda. Nature. 1972, 238, 37. TiO 2 + 2 hv 2 e – +2 h + (1) (at the TiO 2 electrode) 2 H + + 2 e – H 2 (2) (at the Pt electrode) H 2 O + 2 h + 1/2 O 2 + 2 H + (3) (at the TiO 2 electrode) H 2 O + 2 hv 1/2 O 2 + H 2 (4) (overall reaction) Mechanism of photocatalytic water splitting

9. 9 Pt H+H2H+H2 hv H2OO2H2OO2 h+h+ e- VB CB RuO 2 Schematic Water oxidation and reduction process over photocatalyst

10. 10 h+h+ e- VB CB H + /H 2 O 2 /H 2 O 2 1 0 E vs NHE(pH=0) 0 V 1.23 V badgap The relationship between the redox potential of H 2 O and the VB-CB of the semiconductor

11. 11 e-e- e-e- e - +h + h+h+ h+h+ H+H2H+H2 H2OO2H2OO2 CB VB h+h+ e-e- hv Schematic photoexicitation process in semiconductor

12. 12 Solar energy distribution detected at PM 12 in Japan

13. 13 Vis 400-700nm UV <400nm IR >700nm

14. 14 O2p N2p M nd CB VB S3p Energy level diagram of transition metal oxide, nitride and sulfide

15. 15 UV-Vis diffuse reflection spectra for Sm 2 Ti 2 O 7 and Sm 2 Ti 2 S 2 O 5 A. Ishikawa et al, J. Am. Chem. Soc., 2002, 124, 13547. Recent development of water splitting

16. 16 A. Ishikawa et al, J. Am. Chem. Soc., 2002, 124, 13547. Time course of O 2 evolution from Sm 2 Ti 2 S 2 O 5 and CdS under visible light irridiation (Condition catalyst: 0.2g, La2O3, 0.2g, 0.01M AgNO3 solution 200ml )

17. 17 A. Ishikawa et al, J. Am. Chem. Soc., 2002, 124, 13547. Time course of H 2 evolution from 1.0 wt %Pt- Sm 2 Ti 2 S 2 O 5 under visible light irradiation( > 440nm, catalyst, 0.2g; solution volume, 200ml) 0.01M Na 2 SO 3 + 0.01M Na 2 S 20ml CH 3 OH +180ml H 2 O

18. 18 A. Ishikawa et al, J. Am. Chem. Soc., 2002, 124, 13547. Estimated band position of Sm 2 Ti 2 S 2 O 5 at pH = 0 and 8

19. 19 A. Kudo et al, Chem. Comm., 2002, 1958. Diffuse reflection spectra of AgInZn 7 S 9 (a), ZnS (b) and AgInS 2 (c). AgInS 2 AgInZn 7 S 9 ZnS

20. 20 A. Kudo et al, Chem. Comm., 2002, 1958. Photocatalytic H 2 evolution over AgInZn 7 S 9 (a) and 3wt%-Pt /AgInZn 7 S 9 under visible light irradiation( >420nm, catalyst, 0.3g; 0.25 M K 2 SO 3 - 0.35 M Na 2 S solution 300 ml.

21. 21 The set up for photocatalytic water splitting My preliminary work and next plan

22. 22 Low yield part (S<9120) hydrogen evolution standard curve for System-1 and System-2(S-1, S-2) Y = 2.60E-4*X+0. 29 R = 0.99676

23. 23 Middle yield part (9120<S<1400000) hydrogen evolution standard curve for S-1 and S-2 Y = 1.92-4*X+2.31 R = 0.99978

24. 24 Y = 3.18E-4*X-159.6 R = 0.99787 High yield part (S>1400000) hydrogen evolution standard curve for S-1 and S-2

25. 25 Y = 1.92E-3*X-2.63 R = 0.99951 Oxygen evolution standard curve for S-1 and S-2

26. 26 Y =2.56E-3*X-3.50 R = 0.99951 Nitrogen evolution standard curve for S-1 and S-2

27. 27 Time course of H 2 (A) and O 2 (B) evolution over CdO-360 (condition catalyst, 0.5g; 300W xenon lamp) CH 3 OH 30ml, H 2 O 170ml 0.01M AgNO 3 200ml, >420nm

28. 28 Photocatalytic O 2 evolution over CdO calcinated at varying temperature(Condition: catalyst 0.5g, 0.01M AgNO 3 200ml)

29. 29 Effect of La 2 O 3 on the activity of the CdO calcinated at 400°C

30. 30 CdO-500-la 2 O 3 CdO-400-la 2 O 3 Photocatalytic O 2 evolution over CdO calcinated at 400 and 500  C(Condition: catalyst 0.5g; 0.01M AgNO 3 200ml; la 2 O 3, 0.2g)

31. 31 Photocatalytic O 2 evolution over CdO-400 and 1% RuO 2 loaded CdO-400(Condition: catalyst 0.5g; 0.01M AgNO 3 200ml; La 2 O 3, 0.2g)

32. 32 Photocatalytic O 2 evolution over CdO calcinated at 400°C (Condition: catalyst 0.5g, 0.01M AgNO 3 200ml, La 2 O 3 0.2g) R = 11.2  mol/h

33. 33 Photocatalytic O 2 evolution over CdO-500 and RuO 2 loaded CdO- 500(Condition: catalyst 0.5g; 0.01M AgNO 3 200ml; La 2 O 3, 0.2g)

34. 34 Uv-Vis diffuse reflection spectra for CdO prepared at different temperature 360 400 500

35. 35 XRD pattern of CdO calcinated at 360  C

36. 36 200300400500600700800 0.0 0.2 0.4 0.6 0.8 1.0 Intensity(a.u.) wavelengthen / nm CdIn2S4 CdS UV-Vis diffuse reflection spectra for CdS and CdIn 2 S 4 prepared by the solvothermal method.

37. 37 XRD pattern of CdIn2S4 prepared by solvothermal method

38. 38 Next Plans 1To investigate the influence of other electron acceptor such as Fe 3+ and its concentration on the activity of CdO system. 2To explore how the different loading species with varying amount will influence the O 2 evolution. 3To synthesize Cr or Ni doped CdO to enhance the position of VB of CdO. 4To synthesize other sulfide with better activity.