Université de Fribourg

Strongly bound excitons in anatase TiO₂ single crystals and nanoparticles

Baldini, Eduardo ; Chiodo, Letizia ; Dominguez, A. ; Palummo, M. ; Moser, S. ; Yazdi-Rizi, Meghdad ; Auböck, G. ; Mallett, Benjamin P. P. ; Berger, Helmuth ; Magrez, Arnaud ; Bernhard, Christian ; Grioni, M. ; Rubio, Angel ; Chergui, Majed

In: Nature Communications, 2017, vol. 8, no. 1, p. 13

Anatase TiO₂ is among the most studied materials for light-energy conversion applications, but the nature of its fundamental charge excitations is still unknown. Yet it is crucial to establish whether light absorption creates uncorrelated electron–hole pairs or bound excitons and, in the latter case, to determine their character. Here, by combining steady-state angle-resolved...

Université de Fribourg

Evaluation of the toxicity of graphene derivatives on cells of the lung luminal surface

Horváth, Lenke ; Magrez, Arnaud ; Burghard, Marko ; Kern, Klaus ; Forró, László ; Schwaller, Beat

In: Carbon, 2013, vol. 64, p. 45–60

Graphene-based nanomaterials are expected to have a profound impact on a broad range of applications. However, studies devoted to investigating the putative adverse health effects of these nanomaterials are hugely underrepresented in the current scientific literature. We have investigated the in vitro short-term cellular toxicity associated with graphene derivatives (GD): graphene oxide and...

Université de Fribourg

In vitro investigation of the cellular toxicity of boron nitride nanotubes

Horváth, Lenke ; Magrez, Arnaud ; Golberg, Dmitri ; Zhi, Chunyi ; Bando, Yoshio ; Smajda, Rita ; Horváth, Endre ; Forró, Lászlo ; Schwaller, Beat

In: ACS Nano, 2011, vol. 5, no. 5, p. 3800–3810

Nanotubes present one of the most promising opportunities in nanotechnology with a plethora of applications in nanoelectronics, mechanical engineering, as well as in biomedical technology. Due to their structure and some physical properties, boron nitride (BN) nanotubes (BNNTs) possess several advantages over carbon nanotubes (CNTs), and they are now commercially produced and used on a large...

Université de Fribourg

Cellular toxicity of TiO₂-based nanofilaments

Magrez, Arnaud ; Horvth, Lenke ; Smajda, Rita ; Salicio, Valérie ; Pasquier, Nathalie ; Forró, László ; Schwaller, Beat

In: ACS Nano, 2009, vol. 3, no. 8, p. 2274–2280

At present, nanofilaments are not exclusively based on carbon atoms but can be produced from many inorganic materials in the form of nanotubes and nanowires. It is essential to systematically assess the acute toxicity of these newly synthesized materials since it cannot be predicted from the known toxicity of the same material in another form. Here, the cellular toxicity of TiO₂-based...