First-principles study on the stability, electronic structure, and band alignment of AgNbO3 surfaces: Understanding the adsorption process of H2O and O2

• Published in: Computational materials science 2025-01, Vol.246, p.113398, Article 113398
• Main Authors: Carvalho de Oliveira, Marisa, Longo, Elson, Ribeiro, Renan A.P., Lemos, Samantha C.S., Andrés, Juan, Gracia, Lourdes
• Format: Article
• Language: English
• Subjects: adsorption of H2O and O2; AgNbO3; DFT calculations; Reactive oxygen species; Urfaces
• ISSN: 0927-0256
• DOI: 10.1016/j.commatsci.2024.113398

[Display omitted] •DFT calculations were employed to reveal the electronic and catalytic properties of AgNbO3 surfaces.•Theoretical results help us to predict the morphological modulations of AgNbO3 and their possible shapes.•Undercoordinated centers on these surfaces act as frustrated Lewis base and acid pairs.•These sites control the selectivity of AgNbO3 to bind H2O/O2 molecules, opening an energetically favorable pathway for the production of ROS. In this work, DFT calculations have been employed to delve into the structural, electronic, and optical properties of low-index (010), (100), (101), (110), (011), and (114) surfaces of AgNbO3. Wulff construction was used to predict the available morphologies of this material and their transformations, which were matched with the experimental images obtained by electron microscopy to support our findings. Our data indicate that the undercoordinated O anions and Ag and Nb cations on these surfaces act as frustrated Lewis base and acid pairs, respectively, to control their structure and electronic properties. These sites at the (110) and (010) selectively bind H2O and O2 molecules, opening an energetically favorable pathway for the dissociation of H2O to enhance the initial stages of the formation of reactive oxygen species, ⋅OH, ⋅O2− and ⋅OOH radicals, which adsorbed strongly on both surfaces within a simplified model. Overall, the results demonstrate that careful consideration of the impacts of surface chemistry on the behavior of AgNbO3 surfaces is required to further understand and tailor the reactivity based on the generation of these highly reactive species.