Integration of Fullerenes as Electron Acceptors in 3D Graphene Networks: Enhanced Charge Transfer and Stability...

Here, we report a concept that allows the integration of the characteristic properties of [60]fullerene in 3D graphene networks. In these systems, graphene provides high electrical conductivity and surface area while fullerenes add high electron affinity. We use molecular design to optimize the interaction between 3D graphene networks and fullerenes, specifically in the context of stability and charge transfer in an electrochemical environment. We demonstrated that the capacity of the 3D graphene network is significantly improved upon the addition of C₆₀ and C₆₀ monoadducts by providing additional acceptor states in the form of low-lying lowest unoccupied molecular orbitals of C₆₀ and its derivative. Guided by experimental results and first-principles calculations, we synthesized and tested a C₆₀ monoadduct with increased stability by strengthening the 3D graphene-C₆₀ van-der-Waals interactions. The synthesis method and stabilization strategy presented here is expected to benefit the integration of graphene-C₆₀ hybrid materials in solar cell and charge storage applications.