Chemistry Makes Graphene beyond Graphene

Abstract

Although graphene is extremely inert in chemistry because of the giant delocalized π electron system, various methods have been developed to achieve its efficient chemical modification. Covalent chemistry is effective to modulate the physical properties of graphene. By converting the sp(2) hybridized carbon atoms to sp(3) ones, new two-dimensional (2D) materials and 2D superlattices with fascinating features beyond mother graphene could be built from the graphene scaffold, greatly expanding the graphene family and its attraction. In this Perspective, the power of covalent chemistry is demonstrated from the viewpoint of tailoring graphene's energy band structure as well as creating new 2D materials and 2D superlattices. A specific focus is laid on the general consideration and understanding of covalent graphene chemistry toward electronic devices and material science.

Flexible and Highly Sensitive Strain Sensors Fabricated by Pencil Drawn for Wearable Monitor

“…[ 9,[30][31][32] Pencil, a day-to-day material, is a nanocomposite of graphite and intercalated clay. [33][34][35] Being layered or pelleted, pencil lead can be exfoliated by using a gentle force.…”

Layer response theory: Energetics of layered materials from semianalytic high-level theory

“…For a layer with inversion symmetry in the z direction, the distinction between fields impinging from left or right disappears, and we just have a reflection coefficient R I and and a transmission coefficient T I given by (6) and (8).…”

“…The interest in two dimensional compounds such as graphene 1 , hexagonal boron nitride 2,3 , transition metal dichalcogenides [2][3][4] , and other promising compounds has grown exponentially over the last few years [5][6][7][8] . In particular, there has been much recent interest in their cohesive properties and also in layered, heterostructured solids composed of loosely-bound stacks of such 2D layers 9 .…”

An interlayer nanostructure of rGO/Sn2Fe-NRs array/rGO with high capacity for lithium ion battery anodes

“…The reduced graphene oxide (rGO) nanosheets are engineered as the substrate and cover, while Sn2Fe nanorods array (NRs array) as interlayer, which results in the formation of rGO/Sn2Fe-NRs array/rGO interlayer nanostructures. The nanostructures can promise the following advantages: 1) the top and bottom graphene layers serve as stable unfolded shells for fast electron transport; 2) Fe in Sn2Fe NRs array, acting as electrochemical inert component, effectively accommodates the large volume expansion of Sn during the charging-discharging process; 3) the enclosed and ordered Sn2Fe NRs array nanostructures exhibit a supreme structural and cycling stability by facilitating the electron transfer as well as providing free volume expansion space for Li + intercalation and deintercalation [24][25][26][27][28]; 4) one dimensional (1D) NRs are very conductive in the sense of directed transmission of electrons, thus enhancing the reversible capacity of the as-synthesized anode materials [29][30][31][32][33][34]; 5) the interlayer nanostructures empower the stability of integral structure while effectively hindering side reactions in LIBs, which further improves specific capacity in a high-rate charging-discharging process; moreover, such graphene covered interlayer nanostructures offer volume expansion space for Sn. The measurement results show that our interlayer nanostructures of rGO/Sn2Fe-NRs array/rGO achieve excellent electrochemical performance.…”