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Near Bandgap Excitation Inhibits the Interfacial Electron Transfer of Semiconductor/Cocatalyst
Jiawei Xue1, Mamoru Fujitsuka1, Tetsuro Majima1
1The Institute of Scientific and Industrial Research (SANKEN) , Osaka University , Mihogaoka 8-1 , Osaka , Ibaraki 567-0047 , Japan.
Abstract:
Understanding the ultrafast interfacial electron transfer (IET) process is essential for establishing the structure-property relationship of the semiconductor/cocatalyst system for photocatalytic H2 evolution. However, the IET kinetics for the near bandgap excitation has not been reported. Herein, we investigate the IET kinetics of g-C3N4/Pt as a semiconductor/cocatalyst prototype by femtosecond time-resolved diffuse reflectance spectroscopy. We find that the near bandgap excitation of g-C3N4 inhibits the IET of g-C3N4/Pt due to electron deep trapping, resulting in a markedly decreased apparent quantum efficiency for photocatalytic H2 evolution. This work complements the kinetic understanding for the photocatalytic mechanism of the semiconductor/cocatalyst system in its whole light absorption range.
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