Spontaneous reduction and assembly of graphene oxide into three-dimensional graphene network on arbitrary conductive substrates

Chemical reduction of graphene oxide (GO) is the main route to produce the mass graphene-based materials with tailored surface chemistry and functions. However, the toxic reducing circumstances, multiple steps, and even incomplete removal of the oxygen-containing groups were involved, and the produced graphenes existed usually as the assembly-absent precipitates. Herein, a substrate-assisted reduction and assembly of GO (SARA-GO) method was developed for spontaneous formation of 3D graphene network on arbitrary conductive substrates including active and inert metals, semiconducting Si, nonmetallic carbon, and even indium-tin oxide glass without any additional reducing agents. The SARA-GO process offers a facile, efficient approach for constructing unique graphene assemblies such as microtubes, multi-channel networks, micropatterns, and allows the fabrication of high-performance binder-free rechargeable lithium-ion batteries. The versatile SARD-GO method significantly improves the processablity of graphenes, which could thus benefit many important applications in sensors and energy-related devices.