Recent Developments in Graphene Quantum Dots in Energy Related Applications: A Review

Recently, graphene quantum dots (GQDs), zero-dimensional flat nanomaterials with distinct optical, electrical, and optoelectric properties, have attracted significant attention, owing to their non-toxicity and physiological inertness. A variety of top-down and bottom-up methodologies have been exploited for the synthesis of these materials, including electrochemical oxidation, hydrothermal or solvothermal, microwave-assisted, controllable synthesis and carbonization from organic molecules or polymers. This review focuses on the synthesis and applications of GQDs in solar cells, supercapacitors, LEDs, and Li/Na ion batteries. Herein, we summarized in detail the synthesis methods for GQDs employed in energy storage applications with enhanced capacitance, power conversion, retention capability, and stability, achieved by adjusting many synthesis parameters, including annealing temperature, growth time, substrate concentration, and catalyst. The conclusion highlights the potential opportunities and challenges related to future research on GQDs.