Cowan, Alexander J. Tang, Junwang Leng, Wenhua Durrant, James R. Klug, David R. Water Splitting by Nanocrystalline TiO<sub>2</sub> in a Complete Photoelectrochemical Cell Exhibits Efficiencies Limited by Charge Recombination We report on the mechanism of water splitting by TiO<sub>2</sub> in the absence of chemical scavengers in a fully functional photoelectrochemical (PEC) cell. The application of a positive potential to a nanocrystalline-TiO<sub>2</sub> film is shown to lead to the formation of long-lived holes which oxidize water on the milliseconds time scale. These first time-resolved studies of a nanocrystalline-TiO<sub>2</sub> (nc-TiO<sub>2</sub>) film in a complete PEC cell also showed that all of the long-lived photoholes go on to generate O<sub>2</sub>, and that there are no major branching inefficiencies in the catalysis itself, which appears to be operating at efficiencies close to 100%. The overall quantum yield of oxygen production under pulsed illumination (355 nm) was found to be ∼8% at excitation densities of 4.4 photons per particle. Under all conditions examined, electron−hole recombination was found to be the dominant loss pathway. Charge Recombination;Nanocrystalline TiO 2;loss pathway;film;TiO 2;oxygen production;4.4 photons;PEC cell;excitation densities;milliseconds time scale;O 2;water Splitting;chemical scavengers;oxidize water;Complete Photoelectrochemical Cell Exhibits Efficiencies Limited;water splitting 2010-03-11
    https://acs.figshare.com/articles/journal_contribution/Water_Splitting_by_Nanocrystalline_TiO_sub_2_sub_in_a_Complete_Photoelectrochemical_Cell_Exhibits_Efficiencies_Limited_by_Charge_Recombination/2785207
10.1021/jp909993w.s001