▎ 摘　　要

Two-dimensional (2D) nanomaterials like graphene (G) and boron nitride (BN) have been used to fabricate nanofluids for applications in thermal management. Both excellent filler dispersion and high thermal conduction are required for the different nanofluids. However, 2D nanofluids that remain in a stable dispersion state, yet with high thermal conductivity, have not yet been developed. Herein, edge-functional 2D composite nanosheets of graphene and boron nitride (G/BN) were synthesized through a green dry ice-assisted ball milling technique. The thermal performance of the G/BN aqueous nanofluids was first investigated. We found that the thermal conductivity of the G/BN aqueous nanofluids was up to 1.62 W mK(-1) at 5 vol % loading. According to the surface temperature changes of a verification system for simulating the heat dissipation process, the G/BN aqueous nanofluids had a higher transfer heat capability than that of pure water. Therefore, G/BN showed great potential in coolant applications.