The Critical Role Played by the Catalytic Moiety in the Early-Time Photodynamics of Hydrogen-Generating Bimetallic Photocatalysts.
The effect of the catalytic moiety on the early-time photodynamics of Ru/M (M=Pt or Pd) bimetallic photocatalysts is studied by ultrafast transient absorption spectroscopy. In comparison to the Ru/Pd photocatalyst described earlier, the Ru/Pt analogue shows complex excited-state dynamics with three distinct kinetic components ranging from sub-ps to 10(2)  ps, requiring a more sophisticated photophysical model than that developed earlier for the Ru/Pd complex. In the Pu/Pt photocatalyst, an additional lower-lying excited state is proposed to quench the hot higher-lying triplet metal-to-ligand charge-transfer states. Furthermore, a strong excitation wavelength dependence on the population of excited states is observed for both the Ru/Pt and Ru/Pd complexes, indicating a non-equilibrated distribution even on the 10(2)  ps timescale. These insights shed light on the significant impact of the catalytic moiety on the fundamental early-time photophysics of Ru-based photocatalysts.
MESA+Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
Qing
Q
Pan
Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, 9747 AG, Groningen, The Netherlands.
Francesco
F
Mecozzi
MESA+Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
Jeroen P
JP
Korterik
SRC for Solar Energy Conversion, School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
Johannes G
JG
Vos
Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, 9747 AG, Groningen, The Netherlands.
Wesley R
WR
Browne
MESA+Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands. j.m.huijser@utwente.nl.
Annemarie
A
Huijser
molecular photocatalysis; non-equilibrated excited states; photodynamics; ruthenium; transient absorption