behavior that is dependent on the sliding history of the contact, which currently remains unexplored and is the focus of the current study.Generating a comprehensive understanding of the dissipation pathways for 2D materials in liquids is crucial for developing predictive models for the friction and wear behavior of 2D materials. [11] The atomic force microscope (AFM) has proven to be a unique and powerful tool to investigate the atomic origins of friction behavior of 2D materials under a well-defined, single-asperity contact and in the absence of wear. Previous experiments using AFM in a dry environment showed that the probe sliding history on the 2D material leads to several unique behaviors such as frictional aging of the contact, [12,13] friction strengthening, [14][15][16][17] and load-dependent friction hysteresis. [18][19][20] The previous load-dependent friction measurements on supported graphene reported lower friction forces while increasing the normal load (loading) than when the load was withdrawn (unloading) at a given normal load, [18,19] displaying friction hysteresis. This behavior is shown to originate from the irreversible transformation of the contact upon loading, caused either by changes in the contact area and/or interaction forces at the sliding interface. [18] Several physical parameters, such as the presence of environmental adsorbates, [21] maximum applied load, [19] temperature, [22] sliding velocity, [23] etc., have been shown to influence the sliding-history-dependent friction behavior for single and as well for few-layer (FL) graphene.In ambient or dry conditions, sliding an AFM probe across the graphene deposited on a copper substrate led to an out-of-theplane deformation of the graphene adjacent to the AFM probe. A higher adhesion during the unloading process, in comparison to loading, resulted in delayed relaxation of the graphene layer (higher contact area) and hence enhanced friction hysteresis. [19] However, the presence of condensed water at the probe-graphene contact suppressed the out-of-plane deformation of graphene but instead led to an irreversible reorganization of water molecules at the contact once loaded. [18] The contact area hysteresis, i.e., the smaller number of water molecules in contact with the probe (contact area) during the loading process, in comparison to unloading, led to friction hysteresis of graphene in a humid environment. [18] The load-dependent friction hysteresis was also observed for bulk graphitic surfaces when the work of adhesion between the AFM probe and the graphitic surface exceeded the Sliding-induced friction behavior of a single-asperity silica probe against fewlayer (FL) graphene and bulk graphite is measured in the presence of n-hexadecane using an atomic force microscope (AFM). The load-dependent nanoscale friction measurements display friction hysteresis, i.e., higher friction forces during unloading of the contact than loading, at a given normal load. However, unlike hysteresis in friction of graphene measured in ambient, several uniq...

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