From Pristine to Heteroatom‐Doped Graphene Quantum Dots: An Essential Review and Prospects for Future Research

Abstract

Graphene quantum dots (GQDs) are carbon‐based zero‐dimensional materials that have received considerable scientific interest due to their exceptional optical, electrical, and optoelectrical properties. Their unique electronic band structures, influenced by quantum confinement and edge effects, differentiate the physical and optical characteristics of GQDs from other carbon nanostructures. Additionally, GQDs can be synthesized using various top‐down and bottom‐up approaches, distinguishing them from other carbon nanomaterials. This review discusses recent advancements in GQD research, focusing on their synthesis and functionalization for potential applications. Particularly, various methods for synthesizing functionalized GQDs using different doping routes are comprehensively reviewed. Based on previous reports, current challenges and future directions for GQDs research are discussed in detail herein.

Nanostructural Characterization of Luminescent Polyvinyl Alcohol/Graphene Quantum Dots Nanocomposite Films

“…To date, there is still a need for a comprehensive understanding of the mechanisms behind the PL emission of GQDs [ 48 , 49 ]. There are three primary contributing factors: size, surface structure, and edge effects.…”

Engineering functionalization and properties of graphene quantum dots (GQDs) with controllable synthesis for energy and display applications

“…44,45 Conversely, elements with electron deficiencies, such as B, tend to lower the LUMO energy level. 46 Feng et al explored GQDs doped with N in various forms and revealed that hetero-doping of B, P, and S atoms leads to a decrease in the HOMO–LUMO gap (Fig. 2a).…”

“…However, more recent studies emphasize band gap tuning through functionalizing GQDs with various functional groups and dopants. 41–46 The introduction of functional groups and dopants into GQDs leads to localized changes in electron density within GQDs. 47–49 This enhances the ion affinity of GQDs and allows them to act as catalysts in specific reactions.…”

A Sandwich-Type Photoelectrochemical Sensor Based on Anthocyanin-Sensitized ZnO/P5FIn Heterojunction for the Sensitive Detection of CYFRA21-1

“…In recent years, natural dyes have garnered widespread attention as sensitizing materials. Due to their broad absorption bands and favorable charge transfer properties, they are often employed to enhance light absorption and improve device performance [20]. Among these natural dyes, anthocyanins stand out as hydroxyl-containing sensitizers with advantages such as simple extraction, low cost, and nontoxicity [21].…”