TY - GEN A1 - Richter, Matthias R. A1 - Cheng, Wen-Hui A1 - Crumlin, Ethan J. A1 - Drisdell, Walter S. A1 - Atwater, Harry A. A1 - Schmeißer, Dieter A1 - Lewis, Nathan S. A1 - Brunschwig, Bruce S. T1 - X‑ray Photoelectron Spectroscopy and Resonant X‑ray Spectroscopy Investigations of Interactions between Thin Metal Catalyst Films and Amorphous Titanium Dioxide Photoelectrode Protection Layers T2 - Chemistry of Materials N2 - The use of electrochemistry, X-ray photoelectron spectroscopy, and resonant X-ray spectroscopy has unlocked the paradox of interfacial hole conduction through amorphous TiO2 (a-TiO2) to deposited Ni, Ir, and Au metal catalysts. Although electrocatalysts for the oxygen-evolution reaction derived from metallic Ir and Ni have mutually similar overpotentials in alkaline media, Si/a-TiO2/Ir interfaces exhibit higher overpotentials than Si/a-TiO2/Ni interfaces. The data allow formulation of full band energy diagrams for n-Si/a-TiO2/metal interfaces for M = Ni, Ir, or Au. Although both Ni and Ir produce band bending in a-TiO2 favoring hole conduction, only Ni creates multiple states within the a-TiO2 band gap at the a-TiO2/Ni interface, which produces a quasi-metallic interface at the a-TiO2/Ni junction. Au, however, produces a flat-band interface that limits hole conduction without any new band gap states. KW - X‑ray Photoelectron Spectroscopy KW - Resonant X‑ray Spectroscopy KW - titanium oxide KW - oxygen-evolution reaction KW - protection layer KW - interface interaction Y1 - 2021 U6 - https://doi.org/10.1021/acs.chemmater.0c04043 SN - 0897-4756 SN - 1520-5002 VL - 33 IS - 4 SP - 1265 EP - 1275 ER -