Exfoliated and plicated g-C3N4 nanosheets for efficient photocatalytic organic degradation and hydrogen evolution. (17th June 2021)

• Record Type: Journal Article
• Authors: Beyhaqi, Ahmad; Azimi, Seyed Mohammad Taghi; Chen, Zhihong; Hu, Chun; Zeng, Qingyi
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 39(2021)
• Page Start: 20547
• Page End: 20559
• Publication Date: 2021-06-17
• Subjects: G-C3N4 nanosheets -- Acidic etching -- Photocatalysis -- Exfoliation -- Wastewater treatment -- Hydrogen generation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.03.174
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Exfoliated and plicated g-C3 N4 nanosheets (CNsF) were prepared through a thermal-chemical exfoliation in which the bulk g-C3 N4 was obtained first under thermal exfoliation, and then was exposed to an acidic etching using hydrofluoric acid under hydrothermal condition. The acidic etching not only exfoliated g-C3 N4 nanosheets by disrupting weak van der Waals forces between layers, which led to formation of a monolayer or a few layers of g-C3 N4 nanosheets, but also made disordered defects on its surface and created plicated g-C3 N4 nanosheets. Under visible-light illumination, the optimized sample (CNsF-6%) showed a hydrogen evolution rate of 54.13 μmol h −1 g −1 (without co-catalyst) and a specific surface area of 121.4 m 2 g −1, which were about 4.7 and 2.5 times, respectively, higher than pristine g-C3 N4 . It also showed remarkably enhanced photocatalytic performance in removing various organic pollutants. This remarkable improvement probably arises from the porous nanosheets and an increased number of active sites resulting from the CNsF, which subsequently enhanced the charge separation efficiency. This work provided an alternative way to obtain highly active g-C3 N4 photocatalysts. Graphical abstract: Efficiently improved organics degradation and hydrogen generation is acquired using a novel exfoliated and plicated 2-D g-C3 N4 nanosheets which have improved spatial separation of charge carries. Image 1 Highlights: The modified g-C3N4 is prepared by a facile co-calcination and a hydrothermal process. HF Acid treatment is helpful in increasing specific surface area and active sites. High rates of degradation and H2 generation are obtained for optimized sample. The abundant pores with mesoporous structures facilitate charge separation. An H2 generation rate of 54.13 μmol h-1g-1 without using noble metals is achieved.