Reduce and concentrate graphene quantum dot size via scissors: vacancy, pentagon-heptagon and interstitial defects in graphite by gamma rays. (26th October 2021)

• Record Type: Journal Article
• Authors: Ma, Tianshuai; Xue, Yanling; Wang, Wei; Shi, Haiting; Yan, Minjie; Pei, Xiaoyuan; Xu, Zhiwei; Li, Nan; Hong, Chunxia
• Is Part Of: Journal of physics. Volume 34:Number 1(2022)
• Publication Date: 2021-10-26
• Subjects: graphene quantum dots -- γ-rays -- ultrafine particle size -- narrow size distribution; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ac0be8
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Graphene quantum dots (GQDs) with ultrafine particle size and centralized distribution have advantages of small size, narrow size distribution and large specific surface area, which make it be better applied in bioimaging, drug delivery and so on. In our research, we used graphite irradiated by γ -rays to successfully prepare GQDs with ultrafine particle size, narrow size distribution and high quantum yields through solvothermal method. Vacancy defects, pentagon–heptagon defects and interstitial defects were introduced to graphite structure after irradiation, which caused the abundance and concentrated distribution of defects. The defects generated by irradiation could damage the lattice structure of graphite to make it easy for introduction of C–O–C inside graphite sheets. The oxygen-containing functional groups in graphene oxide (GO) increased and centrally distributed after irradiation in graphite, especially for C–O–C group, which were beneficial for cutting of GO and grafting of functional groups in GQDs. Therefore, average size of GQDs was successfully reduced to 1.43 nm and concentrated to 0.6–2.4 nm. After irradiation in graphite, the content of carbonyl and C–N in GQDs had a promotion, which suppressed non-radiative recombination and upgraded the quantum yields to 13.9%.