McCool, Nicholas S. Swierk, John R. Nemes, Coleen T. Saunders, Timothy P. Schmuttenmaer, Charles A. Mallouk, Thomas E. Proton-Induced Trap States, Injection and Recombination Dynamics in Water-Splitting Dye-Sensitized Photoelectrochemical Cells Water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs) utilize a sensitized metal oxide and a water oxidation catalyst in order to generate hydrogen and oxygen from water. Although the Faradaic efficiency of water splitting is close to unity, the recombination of photogenerated electrons with oxidized dye molecules causes the quantum efficiency of these devices to be low. It is therefore important to understand recombination mechanisms in order to develop strategies to minimize them. In this paper, we discuss the role of proton intercalation in the formation of recombination centers. Proton intercalation forms nonmobile surface trap states that persist on time scales that are orders of magnitude longer than the electron lifetime in TiO<sub>2</sub>. As a result of electron trapping, recombination with surface-bound oxidized dye molecules occurs. We report a method for effectively removing the surface trap states by mildly heating the electrodes under vacuum, which appears to primarily improve the injection kinetics without affecting bulk trapping dynamics, further stressing the importance of proton control in WS-DSPECs. Recombination Dynamics;proton control;electron lifetime;injection kinetics;dye molecules causes;dye molecules;metal oxide;water oxidation catalyst;proton intercalation;water splitting;quantum efficiency;recombination mechanisms;time scales;TiO 2;surface trap states;photogenerated electrons;Proton intercalation forms nonmobile surface trap states;recombination centers;Faradaic efficiency 2016-06-13
    https://acs.figshare.com/articles/journal_contribution/Proton-Induced_Trap_States_Injection_and_Recombination_Dynamics_in_Water-Splitting_Dye-Sensitized_Photoelectrochemical_Cells/3458369
10.1021/acsami.6b05362.s001