Ground and excited state charge transfer at aqueous nanodiamonds

authored by: Thorren Kirschbaum, Xiangfei Wang, Annika Bande
Abstract: Nanodiamonds (NDs) are unique carbonaceous materials with exceptionally high stability, hardness, and notable electronic properties. Their applications in photocatalysis, biomedicine, and energy materials are usually carried out in aqueous environments, where they interact with aqueous adsorbates. Especially, electron density may rearrange from the diamond material toward oxidative adsorbates such as oxygen, which is known as charge transfer doping. In this article, we quantify the charge transfer doping for NDs with inhomogeneous surface coverings (hydroxyl, fluorine, and amorphous carbon), as well as NDs doped with heteroatoms (B, Si, N) using hybrid density functional theory (DFT) calculations. The transfer doping magnitude is largely determined by the NDs' highest occupied molecular orbital energies, which can in turn be modified by the surface covering and doping. However, local modifications of the ND structures do not have any local effects on the magnitude of the charge transfer. We furthermore analyze the impact of aqueous adsorbates on the excited states of an aqueous ND in the context of photocatalysis via time-dependent DFT. Here, we find that the excited electrons are biased to move in the direction of the respective oxidative adsorbate. Surprisingly, we find that also unreactive species such as nitrous oxide may attract the excited electrons, which is probably due to the positive partial charge that is induced by the local N (Formula presented.) O solvation geometry.
Organisation(s): Institute of Inorganic Chemistry
External Organisation(s): Freie Universität Berlin (FU Berlin)
Helmholtz-Zentrum Berlin für Materialien und Energie (HZB)
Type: Article
Journal: Journal of computational chemistry
Volume: 45
Pages: 710-718
No. of pages: 9
ISSN: 0192-8651
Publication date: 15.03.2024
Publication status: Published
Peer reviewed: Yes
Electronic version(s): https://doi.org/10.1002/jcc.27279 (Access: Open)

BibTeX

@article{6873c55929434654beb9b263c92a9653,
title = "Ground and excited state charge transfer at aqueous nanodiamonds",
abstract = "Nanodiamonds (NDs) are unique carbonaceous materials with exceptionally high stability, hardness, and notable electronic properties. Their applications in photocatalysis, biomedicine, and energy materials are usually carried out in aqueous environments, where they interact with aqueous adsorbates. Especially, electron density may rearrange from the diamond material toward oxidative adsorbates such as oxygen, which is known as charge transfer doping. In this article, we quantify the charge transfer doping for NDs with inhomogeneous surface coverings (hydroxyl, fluorine, and amorphous carbon), as well as NDs doped with heteroatoms (B, Si, N) using hybrid density functional theory (DFT) calculations. The transfer doping magnitude is largely determined by the NDs' highest occupied molecular orbital energies, which can in turn be modified by the surface covering and doping. However, local modifications of the ND structures do not have any local effects on the magnitude of the charge transfer. We furthermore analyze the impact of aqueous adsorbates on the excited states of an aqueous ND in the context of photocatalysis via time-dependent DFT. Here, we find that the excited electrons are biased to move in the direction of the respective oxidative adsorbate. Surprisingly, we find that also unreactive species such as nitrous oxide may attract the excited electrons, which is probably due to the positive partial charge that is induced by the local N (Formula presented.) O solvation geometry.",
keywords = "DFT, excited states, molecular modeling, nanodiamonds, transfer doping",
author = "Thorren Kirschbaum and Xiangfei Wang and Annika Bande",
year = "2024",
month = mar,
day = "15",
doi = "10.1002/jcc.27279",
language = "English",
volume = "45",
pages = "710--718",
journal = "Journal of computational chemistry",
issn = "0192-8651",
publisher = "John Wiley and Sons Inc.",
number = "11",
}