Stitching Graphene Sheets with Graphitic Carbon Nitride: Constructing a Highly Thermally Conductive rGO/g-CN Film with Excellent Heating Capability.

Driven by the evolution of electronic packaging technology for high-dense integration of high-power, high-frequency, and multi-function devices in modern electronics, thermal management materials have become a crucial component for guaranteeing the stable and reliable operation of devices. Because of its admirable in-plane thermal conductivity, graphene is considered as a desired thermal conductor. However, the promise of graphene films has been greatly weakened as the existence of grain boundaries lead to a high extent of phonon scattering. Here, a stitching strategy is adopted to fabricate an rGO/g-CN film, where 2D g-CN works as a linker to covalently connect adjacent rGO sheets for expanding the size of graphene and forming an in-plane rGO/g-CN heterostructure. The in-plane thermal conductivity of the rGO/g-CN film reaches 41.2 W m K at a g-CN content of only 1 wt %, which increased by 17.3% compared to pristine rGO. The interfaced thermal resistance between rGO and g-CN is further examined by non-equilibrium molecular dynamics simulations. Furthermore, owing to the unique light absorption and welding ability of g-CN, the rGO/g-CN film presents superior solar-thermal and electric-thermal responses to controllably regulate the chip temperature against overcooling. This work provides a facile approach to construct a large-sized rGO sheet and combines heat dissipation and heating capability in the same thermal management material for future electronics.