Towards free-standing graphane: atomic hydrogen and deuterium bonding to nano-porous graphene

Abstract

Graphane is formed by bonding hydrogen (and deuterium) atoms to carbon atoms in the graphene mesh, with modification from the pure planar sp 2 bonding towards an sp 3 configuration. Atomic hydrogen (H) and deuterium (D) bonding with C atoms in fully freestanding nano porous graphene (NPG) is achieved, by exploiting low-energy proton (or deuteron) non-destructive irradiation, with unprecedented minimal introduction of defects, as determined by Raman spectroscopy and by the C 1s core level lineshape analysis. Evidence of the H-(or D-) NPG bond formation is obtained by bringing to light the emergence of a H-(or D-) related sp 3 -distorted component in the C 1s core level, clear fingerprint of H-C (or D-C) covalent bonding. The H (or D) bonding with the C atoms of free-standing graphene reaches more than 1/4 (or 1/3) at% coverage. This non-destructive H-NPG (or D-NPG) chemisorption is very stable at high temperatures up to about 800 K, as monitored by Raman and x-ray photoelectron spectroscopy, with complete healing and restoring of clean graphene above 920 K. The excellent chemical and temperature stability of H-(and D-) NPG opens the way not only towards the formation of semiconducting graphane on large-scale samples, but also to stable graphene functionalisation enabling futuristic applications in advanced detectors for the βspectrum analysis.

Physical and Chemical Activation of Graphene-Derived Porous Nanomaterials for Post-Combustion Carbon Dioxide Capture

“…The fitting parameters including contribution assignment, Full Width at Half Maximum (FWHM) and contribution concentration are given in Table 4 and Table 5 . The contribution at 284.2–284.8 eV is assigned to the sp 2 /sp 3 carbon atoms in C=C graphene network and/or carbon atoms belonging to C-H bonds [ 32 , 33 , 34 , 35 ]. Higher C1s binding energy can be assigned to carbon linked to oxygen: C-O around 286 eV, C=O around 287 eV, and O=C-O at 287–289 eV.…”

Strain-tuning of the electronic, optical, and vibrational properties of two-dimensional crystals

“…H-ion irradiation systematically creates ML-thick domes in at least six TMD materials (WS 2 , WSe 2 , WTe 2 , MoS 2 , MoSe 2 , and MoTe 2 112 ), whereas in hexagonal boron nitride (h-BN), multilayer bubbles were successfully formed by a H-plasma treatment. 136 In graphite/graphene, on the other hand, low-energy H ions preferentially bind to the C atoms toward the formation of graphane, [137][138][139] so that these methods do not yield any bubbles, unless much higher proton energies ($0.5 MeV) are employed. 140 However, even in this case, the resulting structures are not filled with H 2 molecules, but rather with the products of the interaction between the highly energetic protons and the SiO 2 substrate.…”

Heisenberg's uncertainty principle in the PTOLEMY project: a theory update

“…, is m ν < 0.8 eV at 90% C.L., as obtained by the KATRIN experiment using gaseous molecular tritium [13,14]. As far as the cosmic neutrino background is concerned, instead, one could in principle detect it via the process of neutrino capture [15][16][17][18][19][20][21][22][23]. In this case, if the process happens in vacuum, the energy of the emitted electron is expected to be larger than the endpoint by twice m ν .…”