Recent Progress on Functionalized Graphene Quantum Dots and Their Nanocomposites for Enhanced Gas Sensing Applications

• Published in: Nanomaterials (Basel, Switzerland) Vol. 14; no. 1; p. 11
• Main Authors: Balakrishnan, Thivyah, Sagadevan, Suresh, Le, Minh-Vien, Soga, Tetsuo, Oh, Won-Chun
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.12.2023; MDPI
• Subjects: Air pollution; Analysis; Composite materials; Construction methods; Cost analysis; Current carriers; Detection limits; functionalized GQDs; gas sensing mechanism; Gas sensors; Gases; GQDs based nanocomposite; Graphene; Hazardous materials; Heterojunctions; Identification and classification; improved sensing; Metal oxides; Methods; Nanocomposites; Nanoparticles; Nitrogen dioxide; Outdoor air quality; Parameter sensitivity; Polymers; Properties; Quantum dots; Recovery time; Review; Reviews; Sensors; Temperature; Tin dioxide; Toxicity; Two dimensional materials; VOCs; Volatile organic compounds; Vietnam; South Korea; Malaysia; improved sensing; GQDs based nanocomposite; gas sensing mechanism; functionalized GQDs
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano14010011

Gas-sensing technology has witnessed significant advancements that have been driven by the emergence of graphene quantum dots (GQDs) and their tailored nanocomposites. This comprehensive review surveys the recent progress made in the construction methods and applications of functionalized GQDs and GQD-based nanocomposites for gas sensing. The gas-sensing mechanisms, based on the Fermi-level control and charge carrier depletion layer theory, are briefly explained through the formation of heterojunctions and the adsorption/desorption principle. Furthermore, this review explores the enhancements achieved through the incorporation of GQDs into nanocomposites with diverse matrices, including polymers, metal oxides, and 2D materials. We also provide an overview of the key progress in various hazardous gas sensing applications using functionalized GQDs and GQD-based nanocomposites, focusing on key detection parameters such as sensitivity, selectivity, stability, response and recovery time, repeatability, and limit of detection (LOD). According to the most recent data, the normally reported values for the LOD of various toxic gases using GQD-based sensors are in the range of 1-10 ppm. Remarkably, some GQD-based sensors exhibit extremely low detection limits, such as N-GQDs/SnO (0.01 ppb for formaldehyde) and GQD@SnO (0.10 ppb for NO ). This review provides an up-to-date perspective on the evolving landscape of functionalized GQDs and their nanocomposites as pivotal components in the development of advanced gas sensors.