Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (08): 1632-1638.doi: 10.3866/PKU.WHXB201304281

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Application of Time-Resolved Coherent Anti-Stokes Raman Scattering Technique on the Study of Photocatalytic Hydrogen Production Kinetics

LV Yong-Gang1,3, LI Zhi-Jun2, WU Li-Zhu2, WANG Peng1, FU Li-Min1, ZHANG Jian-Ping1   

  1. 1 Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China;
    2 Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China;
    3 School of Physics, Peking University, Beijing 100871, P. R. China
  • Received:2013-01-31 Revised:2003-04-28 Published:2013-07-09
  • Contact: FU Li-Min E-mail:lmfu@chem.ruc.edu.cn
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2009CB220008).

Abstract:

Based on the laser pulse output from a femtosecond regenerative amplifier and optical parametric amplifier (OPA), a broadband time-resolved coherent anti-Stokes Raman scattering (CARS) setup was assembled. Using this setup, the relationship of hydrogen CARS spectra to its amount in a mixture with air and the relevant detection time-delay were studied. Hydrogen CARS spectra without nonresonant background interference were obtained by adjusting the detection time-delay. The observed CARS intensity exhibited a linear relationship with the square of hydrogen concentration, which is consistent with the theoretical prediction. The signal-to-noise ratio showed that when the pressure of hydrogen-air mixed gas was 0.1 MPa, the detection limit of our setup was less than 0.2%. Using this setup, the hydrogen production kinetics of a platinum(II) terpyridyl acetylide molecular-cobalt catalysttriethanolamine (TEOA) system was studied. The kinetic mechanism of hydrogen production was discussed by considering the effect of changing pH. The results indicate that a high proton concentration will reduce the hydrogen production efficiency. This can be attributed to the inhibition of hydrolysis of TEOA under acidic conditions, because it is the electron and proton donor in this hydrogen production system.

Key words: Coherent anti-Stokes Raman scattering, Nonresonant background, Time-resolved spectrum, Photo-catalysis, Kinetics

MSC2000: 

  • O643