2026-10-08 インペリアル・カレッジ・ロンドン（ICL）
Electrochemical Mass Spectrometry (EC-MS) equipment at Royce at Imperial
＜関連情報＞
- https://www.imperial.ac.uk/news/articles/engineering/materials/2026/new-technique-reveals-hidden-losses-in-solar-water-splitting/
- https://pubs.acs.org/jacsat/article/148/39/41739/5439333/Linking-Oxygen-Evolution-Selectivity-to-Water
オペランド光電気化学質量分析法によるヘマタイト光アノード上での水酸化反応次数と酸素発生選択性の関連付け Linking Oxygen Evolution Selectivity to Water Oxidation Reaction Order on Hematite Photoanodes by Operando Photoelectrochemical Mass Spectrometry
Daniele Benetti;Soren B. Scott;Shijie Yu;James Murawski;Caiwu Liang;Anna Winiwarter;Guangmeimei Yang;Andreas Kafizas;Anna Hankin;Ifan E. L. Stephens;James R. Durrant;Flurin Eisner
Journal American Chemical Society Published:September 26, 2026
DOI:https://doi.org/10.1021/jacs.6c11949
Abstract
Water oxidation on metal-oxide (photo)anodes is often assumed to yield molecular oxygen. Here, we combine operando photoelectrochemical mass-spectrometry oxygen detection with spectroelectrochemical rate law analyses to link oxygen selectivity to surface-hole density on hematite photoanodes. At low current and hole densities, where first-order kinetics dominate, a near-zero Faradaic efficiency for oxygen evolution is observed, revealing that isolated single-hole water oxidation is poorly coupled to molecular oxygen formation. Increasing surface-hole density sharply increases O2 Faradaic efficiency, showing that the kinetic crossover to cooperative third-order water oxidation is also a selectivity switch toward O2 evolution. Equivalent behavior under dark electrochemical operation shows that multihole chemistry is intrinsic to hematite and governs selective oxygen evolution, likely representing a general feature of semiconducting metaloxides.
