Diamane: design, synthesis, properties, and challenges

Abstract

Diamane, the two-dimensional counterpart of diamond, is achieved from bi-layer graphene (BlG) or few-layer graphene (FlG) through surface chemical adsorption or high-pressure technology. Diamane with interlayer sp 3 bonding is found to have excellent heat transfer, ultralow friction, high natural frequency, and tunable band gap, which shows the potential technological and industrial applications in nano-photonics, ultrasensitive resonator-based sensors, and improved wear resistance. in this review, we summarize the structure character, synthesis strategies, and physical properties of different diamanes, including hydrogenated diamane (hD), fluorinated diamane (FD), and pristine diamane (PD). in addition, we discuss the effect of functional groups, element doping, and stacking order on the physical properties of diamane. Finally, the remaining challenges and future opportunities for the further development of diamane are addressed.

Progress in Diamanes and Diamanoids Nanosystems for Emerging Technologies

“…The C 2 H unit of diamane has an AB stacking sequence and the isomer of diamane (diamane-II) has an AA stacking sequence, which strongly affects its physical and chemical properties. [1,45,47,48] The AA stacked chain isomers of graphene are the most stable structure, and under pressure it lays the foundation of 3D graphene crystals in hydrogenated form as well. [49] With this configuration, genuine diamane is formed, but if the bilayer graphene is twisted to a certain angle normally up to 30˚, Moire's pattern is formed on the graphene layers.…”

“…[1] The lowest energy per atom is exhibited by AB and ABC stacked diamanes, which accounts for the different structures of diamanes. [31,48,59] To avoid misperception, it is necessary to point out that diamond nanocrystals are different from diamanes, because of the hybridization of carbon atoms and interlayer CAC stacking pattern within the structural domains. [65] Correspondingly, three alternating graphene layers in ABC stacking form cubic diamond, and on the other hand, two alternating graphene layers in AA stacking produces hexagonal diamond.…”

“…The interlayer interaction of bilayered graphene provides the characteristics of superconductivity in its magicangle of 1.1˚. [48] The coupling of electronic phonon will also help to provide superconductivity in diamane which is useful for the next generation of nanoelectronics. [60] Another class of diamanes called Janus and non-Janus structured diamanes, exhibits exceptional thermal and electrical conductivity and quite different physical properties in comparison to normal bilayered diamanes.…”

Structural, Electronic, and Mechanical Properties of 2D Oxidized Diamond (100) Nanofilms

“…[ 1 ] The dimensional effect has been accepted as an important route to modulate the electronic properties. [ 2 ] Stimulated by the successful synthesis of graphene, 2D materials have received much attention due to their unique structures, fascinating properties, and a wide range of technological applications. [ 3 ] The structural stability of diamene was first predicted in 2009, [ 4 ] then several theoretical works devoted on converting multilayer graphene into ultrathin diamond films by attaching hydrogen (H) or fluorine (F) atoms to the outer surface of graphene.…”

“…Before the experimental advance, many theoretical works have been performed on 2D diamonds. [ 2,15–21 ] Our group have systemically investigated the structural and electronic properties of atomically thick diamond nanofilms (DNFs) modulated by crystal orientation, layer thickness, [ 22–27 ] and surface functionalization with H atoms. [ 23,25–27 ] Noted that the surface termination is necessary for stabilizing the diamond phase.…”