title: Influence of LaFeO3Surface Termination on Water Reactivity.
abstract: The polarity of oxide surfaces can dramatically impact their surface reactivity, in particular, with polar molecules such as water. The surface species that result from this interaction change the oxide electronic structure and chemical reactivity in applications such as photoelectrochemistry but are challenging to probe experimentally. Here, we report a detailed study of the surface chemistry and electronic structure of the perovskite LaFeO3in humid conditions using ambient-pressure X-ray photoelectron spectroscopy. Comparing the two possible terminations of the polar (001)-oriented surface, we find that the LaO-terminated surface is more reactive toward water, forming hydroxyl species and adsorbing molecular water at lower relative humidity than its FeO2-terminated counterpart. However, the FeO2-terminated surface forms more hydroxyl species during water adsorption at higher humidity, suggesting that adsorbate-adsorbate interactions may impact reactivity. Our results demonstrate how the termination of a complex oxide can dramatically impact its reactivity, providing insight that can aid in the design of catalyst materials.
authors.affiliation: Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: Kelsey A
authors.identifier: http://orcid.org/0000-0002-3431-8290
authors.initials: KA
authors.lastname: Stoerzinger
authors.affiliation: Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.|Department of Physics, Auburn University , Auburn, Alabama 36849, United States.
authors.forename: Ryan
authors.identifier: http://orcid.org/0000-0002-5304-6921
authors.initials: R
authors.lastname: Comes
authors.affiliation: Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: Steven R
authors.identifier: http://orcid.org/0000-0003-1218-839X
authors.initials: SR
authors.lastname: Spurgeon
authors.affiliation: Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: Suntharampillai
authors.initials: S
authors.lastname: Thevuthasan
authors.affiliation: Pohang Accelerator Laboratory , Pohang, Kyungbuk 37673, Korea.
authors.forename: Kyuwook
authors.initials: K
authors.lastname: Ihm
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Ethan J
authors.identifier: http://orcid.org/0000-0003-3132-190X
authors.initials: EJ
authors.lastname: Crumlin
authors.affiliation: Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Chambers