Nadeem Immad M, Penschke Christopher, Chen Ji, Torrelles Xavier, Wilson Axel, Hussain Hadeel, Cabailh Gregory, Bikondoa Oier, Imran Jameel, Nicklin Christopher, Lindsay Robert, Zegenhagen Jörg, Blunt Matthew O, Michaelides Angelos, Thornton Geoff
London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K.
J Am Chem Soc. 2024 Dec 11;146(49):33443-33451. doi: 10.1021/jacs.4c09911. Epub 2024 Nov 25.
Metal-oxide aqueous interfaces are important in areas as varied as photocatalysis and mineral reforming. Crucial to the chemistry at these interfaces is the structure of the electrical double layer formed when anions or cations compensate for the charge arising from adsorbed H or OH. This has proven extremely challenging to determine at the atomic level. In this work, we use a surface science approach, involving atomic level characterization, to determine the structure of pH-dependent model electrified interfaces of TiO(110) with HCl and NaOH using surface X-ray diffraction (SXRD). A comparison with ab initio molecular dynamics calculations reveals the formation of surprisingly compact double layers. These involve inner-sphere bound Cl and Na ions, with respectively H and O/OH in the contact layer. Their exceptionally high electric fields will play a key role in determining the chemical reactivity.
金属氧化物水界面在光催化和矿物重整等诸多领域都很重要。这些界面处的化学过程关键在于，当阴离子或阳离子补偿因吸附H或OH而产生的电荷时所形成的双电层结构。事实证明，在原子层面确定这一结构极具挑战性。在这项工作中，我们采用一种表面科学方法，包括原子层面的表征，利用表面X射线衍射（SXRD）来确定TiO(110)与HCl和NaOH形成的pH依赖型模型带电界面的结构。与从头算分子动力学计算结果的比较揭示了令人惊讶的致密双电层的形成。这些双电层涉及内球层结合的Cl和Na离子，在接触层中分别与H和O/OH结合。它们异常高的电场将在决定化学反应活性方面发挥关键作用。
