Probing the interaction of noble gases with pristine and nitrogen-doped graphene through Raman spectroscopy

Abstract

The interactions of adsorbates with graphene have received increasing attention due to its importance in the development of applications involving graphene-based coatings. Here, we present a study of the adsorption of noble gases on pristine and nitrogen-doped graphene. Single-layer graphene samples were synthesized by chemical vapor deposition (CVD) and transferred to transmission electron microscopy (TEM) grids. Several noble gases were allowed to adsorb on the suspended graphene substrate at very low temperatures. Raman spectra show distinct frequency blue shifts in both the 2Dand G-bands, which are induced by gas adsorption onto high quality single layer graphene (1LG). These shifts, which we associate with compressive biaxial strain in the graphene layers induced by the noble gases, are negligible for nitrogen-doped graphene. Additionally, a thermal depinning transition, which is related to the desorption of a noble gas layer from the graphene surface at low temperatures (ranging from 20 to 35K), was also observed at different transition temperatures for different noble gases. These transition temperatures were found to be 25K for Argon and 35K for Xenon. Moreover, we were able to obtain values for the compressive biaxial strain in graphene induced by the adsorbed layer of noble gases, using Raman spectroscopy. Ab initio calculations confirmed the correlation between the noble gas-induced strain and the changes in the Raman features observed.

A Library of Doped-Graphene Images via Transmission Electron Microscopy

“…In general, the doped-graphene exhibited the diverse potentials with physical and chemical characteristics in further improvement the unexploited and unexplored potential in graphene. Plasma doping Ultracapacitor Capacitance (280 F/g), novel cycle life (>200,000), and high-power capability [39] Pyrolysis Catalyst High O-reduction reaction [43] Thermal annealing in APCVD Organic molecular sensing Novel probing of Rhodamine (RhB) molecules [40] Thermal annealing in APCVD Ultrasensitive molecular sensor Novel sensing of RhB, crystal violet (CRV), and methylene blue (MB) molecules [41] Pyrolysis Catalyst High O-reduction reaction [37] Thermal annealing in CVD Fuel cells High O-reduction reactions, long-term stability, tolerance to crossover and poison [38] Plasma doping NA NA [42] Annealing at 1100 • C Back-gate FET Mobility (6000 cm 2 /Vs) [44] Plasma doping Biosensor High electrocatalytic activity, Novel glucose biosensing with low concentration (0.01 mM) [86] Electrothermal annealing FET Highly edge functionalization of GNRs by N 2 species [87] Wet chemical doping Catalyst Good electrocatalytic activity, long term stability, and tolerance to crossover effect [88] Soft thermal doping NA NA [92,94] Solvothermal doping Fuel cell Enhanced catalytic activity in O-reduction reaction [96] Thermal annealing in APCVD NA NA [95] Obviously, the TEM is an important technique to reveal the morphology, crystalline and chemical structures of nanomaterials. The information that TEM techniques can provide and their implications on applications is based on the assistances of low-magnification TEM, HR-TEM, spherical aberration-corrected HR-TEM, BF-TEM, DP-TEM, DF-TEM, STEM, DF-STEM, STEM_EELS, HAADF-STEM, and micro EDS-TEM.…”

Xenon on Graphene/Pt(111) at Low Temperature: Influence of the Metal Support

“…In particular, in the case of graphene grown on metals, it is important to know whether the reactive or nonreactive nature of the metal has any influence on the growth and structure of the noble gas layer. Some very recent papers have dealt from a theoretical or computational point of view with the adsorption of Xe on single layers of graphene, − with very scarce experimental data and only on free-standing graphene, or even on other novel 2D materials such as phosphorene . However, there is still an important lack of information in the study of noble gases physisorption: To date, there is no experimental report on the adsorption and growth of xenon or other noble gases on metal-supported graphene, to the best of our knowledge.…”