Shear‐Induced Interfacial Structural Conversion of Graphene Oxide to Graphene at Macroscale

Abstract

The controllable adjustment of an ideal graphene structure on the surface/ interface is important to achieve many of the potential characteristics and applications of graphene. Here, a phenomenon is observed in which friction can induce the structural conversion of graphene oxide (GO) to graphene perfectly on a macroscale sliding interface. The controlling factors and molecular interaction mechanism are further revealed by experiments and theoretical simulation. The results show that shear force drives the tribochemical reactions between the-OH group of GO and active bond of the counterpart, as well as the-OH groups of adjacent GO sheets, leading to the breakage of the COH bond. This leads to the transformation of the sp 3 C to sp 2 C, thereby forming a perfect sixmembered ring. The as-broken hydroxyl groups combine with the dangling bond of the frictional pair or capture hydrogen from the hydroxyl group of the adjacent GO sheet and generate water molecules. This study provides more information on a novel method of manipulating the interfacial structure of graphene at a macroscale by a simple sliding action. The method also provides a new way of force sensing through the detection of the released H 2 O molecules.

A review of advances in tribology in 2020–2021

“…MD simulation has also made many important contributions to the identification of chemical changes in friction and wear processes between solid interfaces. Gao et al [981] found that friction can induce the structural conversion of GO to graphene perfectly on a macroscale sliding interface. They used ReaxFF MD simulations to study the friction and wear process of GO (Fig.…”

Tribochemistry of Graphene Oxide/Graphene Confined between Iron Oxide Substrates: Implications for Graphene-Based Lubricants

“…In our simulations, we also observed a lot of functional groups detached from GO flakes during the sliding process, in agreement with the observation of GO reduction in tribological experiments. 14,42 To characterize the transfer behaviors of functional groups, we calculated the number of O atoms, originally from the functional groups, still bonded with C atoms of the GO flakes or transferred to Fe atoms of the substrates. This calculated value was further divided by the total number of functional groups to obtain the ratio of retained and transferred functional groups.…”

Centrifugal Force Regularized Laponite@Graphene Hybrid Membranes with Ordered Interlayer Mass Transfer Channels and High Structural Stability for High-Rate Supercapacitors

“…39 Physical treatment can be employed to adjust electrode structures without changing the chemical properties, which is an ideal method to tune the interlayer structure. 40 Shear force, which is proven to adjust nanosheet orientation during polymer composite fabrication, is also considered in the graphene-based membrane preparation strategies. However, shear force has difficulty to solely control the orientation of nanosheets with regular distribution and enhanced interaction.…”

“…Therefore, the inserted additive distribution and interlayer channel regularization strategies are urgently required to control the lamellar structure . Physical treatment can be employed to adjust electrode structures without changing the chemical properties, which is an ideal method to tune the interlayer structure . Shear force, which is proven to adjust nanosheet orientation during polymer composite fabrication, is also considered in the graphene-based membrane preparation strategies.…”