GO/rGO as advanced materials for energy storage and conversion

Recently, GO/rGO has become promising platforms for advanced materials in energy related technologies. Extensive applications of rGO have been explored ina variety of electrochemical energy storage and conversion technologies (e.g., fuel cells, metal–air batteries, supercapacitors, and water splitting devices). In particular, GO/rGO was studied as efficient components in catalysts in fuel cells and metal–air batteries for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), one pair of the most important electrochemical reactions. The promising applications are primarily due to their unique physical and chemical properties, such as high surface area, access to large quantities, tunable electronic/ionic conductivity, unique graphitic basal plane structure, and the easiness of modification or functionalization. Chemical doping with heteroatoms (e.g., N, B, P, or S) into graphitic domains can tune the electronic properties, provide more active sites, and enhance the interaction between carbon structures and oxygen molecules. Meanwhile, GO/rGO has demonstrated excellent performances in electric double-layer capacitors (EDLCs, also known as supercapacitors or ultracapacitors) with excellent volumetric and gravimetric capacitance densities as well as feasibility in design and fabrications. Additionally, rGO holds great promise to be high-performance anode materials in lithium-ion batteries due to its favorable interactions with Li. In this chapter, we will discuss the uses of GO/rGO derivatives in these energy conversion and storage technologies, providing insights and guidance for further optimization and design of multifunctional materials for energy applications.