TY - JOUR AU - Wagstaffe, Michael AU - Dominguez Castro, Adrian AU - Wenthaus, Lukas AU - Palutke, Steffen AU - Kutnyakhov, Dmytro AU - Heber, Michael AU - Pressacco, Federico AU - Dziarzhytski, Siarhei AU - Gleissner, Helena AU - Gupta, Verena Kristin AU - Redlin, Harald AU - Dominguez Garcia, Adriel AU - Frauenheim, Thomas AU - Rubio Secades, Angel AU - Stierle, Andreas AU - Noei, Heshmat TI - Photoinduced dynamics at the water/TiO<sub>2</sub>(101) interface JO - Physical review letters VL - 130 SN - 0031-9007 CY - College Park, Md. PB - APS M1 - PUBDB-2023-00580 SP - 108001 PY - 2023 AB - We present a femtosecond time-resolved optical pump-soft x-ray probe photoemission study in which we follow the dynamics of charge transfer at the interface of water and anatase TiO<sub>2</sub>(101). By combining our observation of transient oxygen O 1s core level peak shifts at submonolayer water coverages with Ehrenfest molecular dynamics simulations we find that ultrafast interfacial hole transfer from TiO<sub>2</sub> to molecularly adsorbed water is completed within the 285 fs time resolution of the experiment. This is facilitated by the formation of a new hydrogen bond between an O<sub>2</sub>c site at the surface and a physisorbed water molecule. The calculations fully corroborate our experimental observations and further suggest that this process is preceded by the efficient trapping of the hole at the surface of TiO<sub>2</sub> by hydroxyl species (-OH), that form following the dissociative adsorption of water. At a water coverage exceeding a monolayer, interfacial charge transfer is suppressed. Our findings are directly applicable to a wide range of photocatalytic systems in which water plays a critical role. LB - PUB:(DE-HGF)16 C6 - 36962043 UR - <Go to ISI:>//WOS:000982435900009 DO - DOI:10.1103/PhysRevLett.130.108001 UR - https://bib-pubdb1.desy.de/record/517619 ER -