Early dynamics of the emission of solvated electrons from nanodiamonds in water

Franziska Buchner (1) , Thorren Kirschbaum (1, 2) , Amélie Venerosy (3) , Hugues Girard (3) , Jean-Charles Arnault (3) , Benjamin Kiendl (4) , Anke Krueger (4, 5) , Karin Larsson (6) , Annika Bande (1) , Tristan Petit (1) , Christoph Merschjann (1)

1 HZB - Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
2 Freie Universität Berlin - Department of Mathematics and Computer Science
3 LEDNA - Laboratoire Edifices Nanométriques
4 Institut für Organische Chemie
5 Wilhelm-Conrad Röntgen Research Center for Complex Materials
6 Uppsala University

Solvated electrons are among the most reductive species in aqueous environment. Diamond materials have been proposed as a promising source for solvated electrons, but the underlying emission process in water remains elusive so far. Here, we show spectroscopic evidence for the emission of solvated electrons from nanodiamonds upon excitation with both deep ultraviolet (255 nm) and visible (400 nm) light using ultrafast transient absorption. The crucial role of surface termination for the emission process is evidenced by comparing hydrogenated, hydroxylated and carboxylated nanodiamonds. Especially, hydrogenated nanodiamonds are able to generate solvated electron upon visible light excitation, while they show a sub-ps recombination due to trap states when excited with deep ultraviolet light. The essential role of surface reconstructions on the nanodiamonds in these processes is proposed based on density functional theory calculations. These results open new perspectives for solar-driven emission of solvated electrons in aqueous phase using nanodiamonds.

Keywords: diamond; nanoparticles; solvated electron; surface chemistry; transient absorption

Domains: Material chemistry

Franziska Buchner, Thorren Kirschbaum, Amélie Venerosy, Hugues Girard, Jean-Charles Arnault, et al.. Early dynamics of the emission of solvated electrons from nanodiamonds in water. 2021. ⟨cea-03468215⟩