Demonstration of tritium adsorption on graphene

Demonstration of tritium adsorption on graphene†
Genrich Zeller, *a Desedea D´ıaz Barrero, ab Paul Wiesen,a Simon Niemes, a
Nancy Tuchscherer, a Max Aker, a Artus M. W. Leonhardt, a Jannik Demand, a
Kathrin Valerius, c Beate Bornschein, a Magnus Schlösser a and Helmut H. Telle b
In this work, we report on studies of graphene exposed to tritium gas in a controlled environment. The
single layer graphene on a SiO2/Si substrate was exposed to 400 mbar of T 2, for a total time of ∼55 h.
The resistivity of the graphene sample was measured in situ during tritium exposure using the van der
Pauw method. We found that the sheet resistance increases by three orders of magnitude during the
exposure, suggesting significant chemisorption of tritium. After exposure, the samples were
characterised ex situ via spatio-chemical mapping with a confocal Raman microscope, to study the
effect of tritium on the graphene structure (tritiation yielding T-graphene), as well as the homogeneity of
modifications across the whole area of the graphene film. The Raman spectra after tritium exposure
were comparable to previously observed results in hydrogen-loading experiments, carried out by other
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groups. By thermal annealing we also could demonstrate, using Raman spectral analysis, that the
structural changes were largely reversible. Considering all observations, we conclude that the graphene
film was at least partially tritiated during the tritium exposure, and that the graphene film by and large
withstands the bombardment by electrons from the b-decay of tritium, as well as by energetic primary
and secondary ions.