LAUSR

Carbon quantum dots (CQD) and graphene quantum dots (GQDs) have been mentioned frequently. They have been selected in recent studies as they have unique and remarkable potential, especially in electrical, optical, and optoelectrical properties. CQD and GQDs have very high chemical and physical stability due to inherent inert carbon material, thus newly recognized as a kind of quantum dots material. Its environmentally friendly, non‐toxic, and naturally inactive nature is also a major attraction for scientists around the world. In this work, CQD and GQDs production methods are discussed in detail, including soft‐template method, hydrothermal method, microwave‐assisted hydrothermal (MAH) method, metal‐catalyzed method, liquid exfoliation method, electron beam lithography method, and others. Additive material has been introduced in CQD and GQDs to increase the ability and performance of CQD and GQDs such as nitrogen, sulfur, chlorine, fluorine, and potassium. In particular, the presence of additive material in CQD and GQDs shows an advantage in terms of energy level, which is very good at achieving specific requirements in properties such as optical, electrical, and optoelectrical. In addition, the existence of functional groups consisting of heteroatoms such as oxygen, nitrogen, sulfur, phosphorus, boron, and so on of zero‐dimensional carbon materials in providing an overabundance of the active electrochemical site for the reaction. The product of CQD and GQDs has various shapes and sizes influenced by several parameters such as synthesis temperature, growth time, source concentration, catalyst, and so on. The application of CQDs and GQDs composites in fuel cells has been clearly and scientifically stated as it has enhanced the performance of fuel cell technology.