3D Vertically Aligned CNT/Graphene Hybrids from Layer-by-Layer Transfer for Supercapacitors

Abstract

The exceptional electrical, optical, thermal and mechanical properties make graphene and carbon nanotubes (CNTs) promising for a large variety of applications, including energy storage. In practice, it is higly important to translator these properties associated with the low-dimensional carbon nanomaterials into bulk materials/devices. Recent theoretical studies have proven that three-dimensional (3D) pillared architectures, consisting of parallel graphene layers intercalated by vertically aligned carbon nanotubes (VA-CNTs) in between, possess desriable transport and mechanical properties in all dimensions while maintaining the excellent properties of their building blocks. However, it remains challenging to experimentally realize such 3D pillared graphene/VA-CNT hybrids. Here, tunable 3D pillared graphene/VA-CNT architectures are formed by chemical vapor deposition, and a template-free contact transfer process is presented, involving the hydrophobic-hydrophobic interactions between graphene and VA-CNTs. The resultant 3D graphene/VA-CNT hybrids are demonstrated to be efficient electrode materials for supercapacitors with good performance. This newly-developed methodology holds great potential for fabricating various 3D architectures with many other materials for a wide range of multifunctional applications, including energy storage, electrical and thermal managements, and flexible electronics.