半导体光电化学制氢是一种重要的、有前景的太阳能应用技术. 其产氢效率取决于光生载流子的产生、分离和传输效率. 深入理解光生载流子的动力学过程对于设计高效的太阳能产氢器件有重要的指导意义. 光电化学和瞬态吸收光谱技术是研究光催化反应微观动力学和机理的强有力手段. 本文介绍作者应用这些技术在半导体光电化学制氢方面所取得的部分最新研究结果, 并对存在的问题和今后研究重点提出了一些看法.
Semiconductor photoelectrochemical hydrogen production is an important and promising technology for utilizing solar energy. The efficiency of hydrogen production depends on the efficiencies of separation and transport of photo-generated carriers. A deep understanding of the behavior of these processes has guiding significance for designing efficient solar hydrogen device. photoelectrochemical and transient absorption spectroscopy methods are powerful tool for studying the microscopic dynamics and mechanism of photocatalytic reaction. This review describes the part of the latest results of the author regarding the semiconductor photoelectrochemical hydrogen production obtained by these methods，and the problems and future research priorities in this field are proposed.
[1] Fujishima A, Honda K. Electrochemical photolysis of water at a semiconductor electrode[J]. Nature, 1972, 238(5358): 37-38.
[2] Turner J A. Sustainable hydrogen production[J]. Science, 2004, 305(5686): 972-974.
[3] Shangguan P, Tong S, Li H, et al. Enhanced photoelectrochemical oxidation of water over undoped and Ti-doped α-Fe2O3 electrodes by electrochemical reduction pretreatment[J]. RSC Advances, 2013, 3(26): 10163-10167.
[4] Cowan A J, Durrant J R. Long-lived charge separated states in nanostructured semiconductor photoelectrodes for the production of solar fuels[J]. Chemical Society Reviews, 2013, 42(6): 2281-2293.
[5] Leng W H, Zhang Z, Zhang J Q, et al. Investigation of the kinetics of a TiO2 photoelectrocatalytic reaction involving charge transfer and recombination through surface states by electrochemical impedance spectroscopy[J]. Journal of Physical Chemistry B, 2005, 109(31): 15008-15023.
[6] Leng W H, Barnes P R F, Juozapavicius M, et al. Electron diffusion length in mesoporous nanocrystalline TiO2 photoelectrodes during water oxidation[J]. Journal of Physical Chemistry Letters, 2010, 1(6): 967-972.
[7] Kennedy J H, Frese K W. Photooxidation of water at α-Fe2O3 electrodes[J]. Journal of the Electrochemical Society, 1978, 125, 709-714.
[8] Soedergren S, Hagfeldt A, Olsson J, et al. Theoretical models for the action spectrum and the current-voltage characteristics of microporous semiconductor films in photoelectrochemical cells[J]. Journal of Physical Chemistry, 1994, 98(21): 5552-5556.
[9] Hagfeldt A, Graetzel M. Light-induced redox reactions in nanocrystalline systems[J]. Chemical Reviews, 1995, 95(1): 49-68.
[10] LengW H(冷文华), Zhu H Q(朱红乔). An investigation of photocatalytic degradation reactions of pollutants by combination of (photo)electrochemical measurements[J]. Journal of Electrochemistry(电化学), 2013, 19(5): 437-443.
[11] Cowan A J, Tang J W, Leng W H, et al. Water s plitting by nanocrystalline TiO2 in a complete photoelectrochemical cell exhibits efficiencies limited by charge recombination[J]. Journal of Physical Chemistry C, 2010, 114(9): 4208-4214.
[12] Bisquert J, Vikhrenko V S. Interpretation of the time constants measured by kinetic techniques in nanostructured semiconductor electrodes and dye-sensitized solar cells[J]. Journal of Physical Chemistry B, 2004, 108(7): 2313-2322.
[13] Barnes P R F, Anderson A Y, Koops S E, et al. Electron injection efficiency and diffusion length in dye-sensitized solar cells derived from incident photon conversion efficiency measurements[J]. Journal of Physical Chemistry C, 2009, 113(3): 1126-1136.
[14] Cowan A J, Leng W, Barnes P R F, et al. Charge carrier separation in nanostructured TiO2 photoelectrodes for water splitting[J]. Physical Chemistry Chemical Physics, 2013, 15(22): 8772-8778.
[15] Cheng X F, Leng W H, Liu D P, et al. Electrochemical preparation and characterization of surface-fluorinated TiO2 nanoporous film and its enhanced photoelectrochemical and photocatalytic properties[J]. Journal of Physical Chemistry C, 2008, 112(23): 8725-8734.
