Superior sponge-like carbon self-doping graphitic carbon nitride nanosheets derived from supramolecular pre-assembly of a melamine–cyanuric acid complex for photocatalytic H2 evolution. (25th January 2021)

• Record Type: Journal Article
• Authors: Li, Lingfeng; Zhang, Juhua; Zhang, Quan; Wang, Xiaohao; Dai, Wei-Lin
• Is Part Of: Nanotechnology. Volume 32:Number 15(2021)
• Publication Date: 2021-01-25
• Subjects: carbon self-doped -- graphitic carbon nitride nanosheets -- supramolecular pre-assembly -- highly crystalline -- photocatalytic H2 evolution; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/abd6d1
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: The photocatalytic evolution of hydrogen (H2 ) from water splitting is considered a promising route to overcome the energy crisis, and the key lies in the preparation of efficient photocatalysts. Herein, superior ordered sponge-like carbon self-doped graphitic carbon nitride (g-C3 N4 ) nanosheets (SCCNS) were prepared via a combined strategy of melamine–cyanuric acid complex supramolecular pre-assembly and solvothermal pre-treatment using ethylene glycol (EG) aqueous solutions (EG:water = 50:50 vol.%) as a solvent and carbon doping source. The following pyrolysis converts the naturally arranged melamine–EG–cyanuric acid supramolecular intermediates to highly crystalline SCCNS with large specific surface areas. The optimal SCCNS-180 exhibits superior photocatalytic H2 evolution activities (∼4393 and 11 320 μ mol h −1 g −1 ) when irradiated with visible light and simulated sunlight; these values are up to ∼17- and ∼18-fold higher than that of bulk g-C3 N4 . The quantum efficiency of SCCNS-180 at λ = 420 nm can reach 6.0%. The excellent photocatalytic performance of SCCNS-180 derives from its distinct ordered sponge-like nanosheet structure with highly crystallinity and the carbon doping, leading to its improved optical absorption, accelerated photoinduced electron–hole pair transfer and separation rate and enlarged specific surface area (134.4 m 2 g −1 ).