Evidence of Ion-Beam-Induced Annealing in Graphene Oxide Films Using in Situ X-Ray Diffraction and Spectroscopy Techniques

Abstract

Ion beam irradiation is one of the methods to tune the properties of graphene oxide (GO) by modifying the ratio of sp 2 and sp 3 hybridization. However, the inherent defects present in GO during its synthesis deteriorate its properties (e.g., reduction efficiency) and are difficult to remove. We have earlier demonstrated the annealing of defects in carbon nanostructures (fullerene, carbon nanotube, and graphene) at a lower fluence of swift heavy ion (SHI) irradiation. In the present work, we have studied the irradiation of the GO film with 120 MeV Au ions at fluences ranging from 10 10 to 10 13 ions/cm 2 . In situ X-ray diffraction measurements showed an increase in the crystallinity of the GO film at low fluence. The irradiated samples showed an increase in the intensity of aromatic carbon bonds by Fourier transform infrared spectroscopy which indicates the maximization of graphitic regions for lower fluences up to 3 × 10 11 ions/cm 2 . Higher fluences of ion beam irradiation indicated the loss in crystallinity and presence of carbyne in Raman measurements. Thermal spike simulations were performed to understand the physical processes involved during ion beam irradiation by estimating the radii of core and halo of the tracks formed by SHI.

From nanohole to ultralong straight nanochannel fabrication in graphene oxide with swift heavy ions

“…13) and was studied in detail in ref. 43,44 . For all ions, the decrease in the I D /I G ratio and broadening of the spectral features are more significant for GO-Z than for GO-M.…”

“…Based on atomistic representations, at least a fraction of the created sp-C chains is expected to be stable (e.g., those joining torn lattice edges 50 ), thus explaining their experimental detection here and in ref. 43,44 . Unterminated sp-C chains (i.e., those with dangling bonds) and oxygen end-capped chains are considered highly reactive.…”

Study of Ion Velocity Effect on the Band Gap of CVD-Grown Few-Layer MoS2

“…Recently, researchers have been investigating the use of alkali halides to reduce the evaporation temperature of transition metal trioxide precursors, thereby reducing the high-temperature requirement in the CVD method. Various methods such as plasma immersion, laser irradiation, and ion beam irradiation , can be used to modify the electronic and optical band gap properties of few-layer MoS 2 for potential applications. ,, Our group has investigated the effects of ion beam irradiation-induced modification of nanostructures, nanocomposites thin films, and 2D materials. − …”

Mass Transport via In-Plane Nanopores in Graphene Oxide Membranes

“…With each created defect the GO is simultaneously reduced. The reduction of GO occurs in the surrounding areas of the defects presumably due to ion-induced heating 45 (see also Figure S3). At higher pore densities, these reduced areas start to overlap with the neighboring pores, resulting in a higher removal of functional groups at the edge and surroundings of the pores.…”