Absorption mechanism of dopamine/DOPAC-modified TiO2 nanoparticles by time-dependent density functional theory calculations

Ronchi C, Soria FA, Ferraro L, Botti S, Di Valentin C (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Materials Today Energy Elsevier

Book Volume: 19

Article Number: 100571

DOI: 10.1016/j.mtener.2020.100571

Abstract

Donor-modified TiO2 nanoparticles are interesting hybrid systems shifting the absorption edge of this semiconductor from the ultra-violet to the visible or infrared light spectrum, which is a benefit for several applications ranging from photochemistry, photocatalysis, photovoltaics, or photodynamic therapy. Here, we investigate the absorption properties of two catechol-like molecules, that is, dopamine and DOPAC ligands, when anchored to a spherical anatase TiO2 nanoparticle of realistic size (2.2 nm), by means of time-dependent density functional theory calculations. By the differential absorbance spectra with the bare nanoparticle, we show how it is possible to determine the injection mechanism. Since new low-energy absorption peaks are observed, we infer a direct charge transfer injection, which, unexpectedly, does not involve the lowest energy conduction band states. We also find that the more perpendicular the molecular benzene ring is to the surface, the more intense is the absorption, which suggests aiming at high molecular packing in the synthesis. Through a comparative investigation with a flat TiO2 surface model, we unravel both the curvature and coverage effects.

Involved external institutions

University of Milano-Bicocca / Università degli Studi di Milano-Bicocca, UNIMIB IT Italy (IT) Friedrich-Schiller-Universität Jena DE Germany (DE)

How to cite

APA:

Ronchi, C., Soria, F.A., Ferraro, L., Botti, S., & Di Valentin, C. (2021). Absorption mechanism of dopamine/DOPAC-modified TiO2 nanoparticles by time-dependent density functional theory calculations. Materials Today Energy, 19. https://doi.org/10.1016/j.mtener.2020.100571

MLA:

Ronchi, Costanza, et al. "Absorption mechanism of dopamine/DOPAC-modified TiO2 nanoparticles by time-dependent density functional theory calculations." Materials Today Energy 19 (2021).

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