TY - JOUR JF - Journal of Physical Chemistry Letters A1 - Zhang, Y A1 - Payne, DT A1 - Pang, CL A1 - Fielding, HH A1 - Thornton, G ID - discovery1473153 N2 - The photochemistry of TiO2 has been studied intensively since it was discovered that TiO2 can act as a photocatalyst. Nevertheless, it has proven difficult to establish the detailed charge-transfer processes involved, partly because the excited states involved are difficult to study. Here we present evidence of the existence of hydroxyl-induced excited states in the conduction band region. Using two-photon photoemission, we show that stepwise photoexcitation from filled band gap states lying 0.8 eV below the Fermi level of rutile TiO2(110) excites hydroxyl-induced states 2.73 eV above the Fermi level that has an onset energy of ?3.1 eV. The onset is shifted to lower energy by the coadsorption of molecular water, which suggests a means of tuning the energy of the excited state. SN - 1948-7185 UR - http://dx.doi.org/10.1021/acs.jpclett.5b01508 N1 - © 2015 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. IS - 17 TI - Non-band-gap photoexcitation of hydroxylated TiO2 EP - 3395 AV - public VL - 6 Y1 - 2015/09/03/ SP - 3391 ER -