Electroluminescence and photocatalytic hydrogen evolution of S, N co-doped graphene oxide quantum dots. Issue 7 (21st January 2022)

• Record Type: Journal Article
• Authors: Cheng, Tzu-Yang; Chou, Feng-Pai; Huang, Sheng-Cih; Chang, Chin-Yuan; Wu, Tung-Kung
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 7(2022)
• Page Start: 3650
• Page End: 3658
• Publication Date: 2022-01-21
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta09917e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : S, N-GOQDs with stable electroluminescence, photoluminescence, and photocatalytic properties have been developed. They can be used as emitters for LED devices and as photocatalysts for hydrogen evolution in photo-electro-chemical energy conversion. Abstract : Heteroatom-doped graphene quantum dots (GQDs) can change the optical, chemical, electrical, and optoelectrical properties of materials and diversify their functions. GQDs can be used in a wide range of applications, including in fluorescent agents, light-emitting diodes, bioimaging, solar cells, optoelectronic detectors, photocatalysts, etc. In this article, we describe the synthesis of S and N co-doped graphene oxide quantum dots (S, N-GOQDs) with stable electroluminescence, photoluminescence, and photocatalytic properties and their optoelectrical applications as an emitter of a light-emitting diode device in electro-optical energy conversion and as a photocatalyst for hydrogen evolution in photo-chemical energy conversion. The synthesized S, N-GOQDs show a high yield and excitation-independent emission. The maximum excitation wavelength and emission wavelength are 371 and 447 nm, respectively; the quantum yield is 61% when excited at 371 nm; and the emission half-width is 40 nm. A bright blue emission with a luminance exceeding 1341 cd m −2 was achieved at 6 V, thus proving the potential of S, N-GOQDs as an emitter in electroluminescence applications. For photocatalytic hydrogen evolution, the system consists of a 0.1 mg mL −1 catalyst in pure water or TEA (1.43 M) + 80% EtOH aqueous solution. In pure water, high reaction rates of 3.001 mol h −1 g −1 were obtained under direct sunlight. In the TEA (1.43 M) + 80% EtOH aqueous solution, an unprecedented efficiency of 71 mmol h −1 g −1 and 6.138 mol h −1 g −1 was obtained under a 500 W Xe lamp and direct sunlight, respectively.