Integrated assembly of 3D graphene networks for construction of all-in-one supercapacitor electrodes

Supercapacitors are a kind of efficient and safe energy storage and conversion devices. The development of new - generation supercapacitors that can be used in portable electronic devices and in next - generation vehicles is increasingly demanded. This crucially depends on the discovery of more efficient and cost - effective n ovel materials. Because of their ultrahigh specific surface areas and excellent conductivity , t hree - dimensional (3D) graphene materials hold great promises for supercapacitors. However, the assembly of graphene building blocks into the supercapacitor electrodes with low intrinsic resistance and high ion conductance is still a challenging issue. I n this work, we have undertaken the challenge and used electrochemically generated copper foams (CuF) as an effective template to directly integrate reduced graphene oxide (rGO) 3D networks . This has led to the construction of all - in - one supercapacitor ele ctrodes (3DrGO@CuF) [1] . The overall procedure in clude s two step s : self - assembly of graphene oxide (GO) on Cu F and electrochemical reduction of GO into rGO. The resulting electrodes are capable of delivering a specific capacitance as high as 623 F g - 1 with high cycling stability. Thus, we have shown that h igh specific capacitance can be achieved with 3D graphene nanostructures without any external pseudo - capacitive species doped [2, 3] . The new method is also cost - effective and environmentally friendl

Design, Assembly, and Fabrication of Two-Dimensional Nanomaterials into Functional Biomimetic Device Systems

Diverse functioning biosystems in nature have inspired us and offered unique opportunities in developing novel concepts as well as new class of materials and devices. The design of bioinspired functional materials with tailored properties for actuation, sensing, electronics, and communication has enabled synthetic devices to mimic natural behavior. Among which, artificial muscle and electronic skin that enable to sense and respond to various environmental stimuli in a human-like way have been widely recognized as a significant step toward robotics applications. Polymer materials have previously been dominant in fabricating such functional biomimetic devices owing to their soft nature. However, lacking multifunctionality, handling difficulty, and other setbacks have limited their practical applications. Recently, versatile and high-performance two-dimensional (2D) materials such as graphene and its derivatives have been studied and proven as promising alternatives in this area. In this chapter, we highlight the recent efforts on fabrication and assembly of 2D nanomaterials into functional biomimetic systems. We discuss the structure-function relationships for the development of 2D materials–based biomimetic devices, their tailoring property features, and their variety of applications. We start with a brief introduction of artificial functional biomimetic materials and devices, then summarize some key 2D materials–based systems, including their fabrication, properties, advantages and demonstrations, and finally present concluding remarks and outlook