Graphene Quantum Dots-Based Advanced Electrode Materials: Design, Synthesis and Their Applications in Electrochemical Energy Storage and Electrocatalysis

Graphene quantum dots (GQDs) have aroused great interest in the scientific community in recent years due to their unique physicochemical properties and potential applications in different fields. To date, much research has been conducted on the ingenious design and rational construction of GQDs-based nanomaterials used as electrode materials and/or electrocatalysts. Despite these efforts, research on the efficient synthesis and application of GQDs-based nanomaterials is still in the early stages of development and timely updates of recent research progress on new design concepts, synthetic strategies, and significant breakthroughs in GQDs-based nanomaterials are highly desired. In light of the above, the effect of synthetic methods on the final product of the GQDs, the GQDs synthesis mechanism, and specific perspectives regarding the effect of the unique surface and structural properties of GQDs (e.g., defects, heteroatom doping, surface/edge state, size, conductivity) on the electrochemical energy-related systems are discussed in-depth in this review. Additionally, this review also focuses on the design of GQDs-based composites and their applications in the fields of electrochemical energy storage (e.g., supercapacitors and batteries) and electrocatalysis (e.g., fuel cell, water splitting, CO(2)reduction), along with constructive suggestions for addressing the remaining challenges in the field.