Facile construction of porous intramolecular g-C3N4-based donor-acceptor conjugated copolymers as highly efficient photocatalysts for superior H2 evolution. (January 2020)

• Record Type: Journal Article
• Authors: Che, Huinan; Liu, Chunbo; Che, Guangbo; Liao, Guangfu; Dong, Hongjun; Li, Chunxue; Song, Ning; Li, Chunmei
• Is Part Of: Nano energy. Volume 67(2020)
• Publication Date: 2020-01
• Subjects: Graphitic carbon nitride -- Melamine formaldehyde resin -- Donor-acceptor conjugated copolymers -- Porous -- Photocatalytic hydrogen evolution activity -- Apparent quantum yield; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2019.104273
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Graphitic carbon nitride (g-C3 N4 ) is an emerging polymeric visible-light photocatalyst with a high stability, but it continues to exhibit low photocatalytic efficiency. Herein, novel intramolecular g-C3 N4 -based donor-acceptor (D-A) conjugated copolymers with a porous structure and large specific surface area, have been facilely prepared by copolymerizing urea with melamine-formaldehyde (MF) resin, which is strategically used for promoting the photocatalytic performance of pure g-C3 N4 . The experimental results indicate that the as-prepared porous intramolecular g-C3 N4 -MFx D-A conjugated copolymers not only enlarge the light utilization but also accelerate the separation of charge carriers because of the enhanced electron-accepting ability due to the introduction of MF resin. In addition, compared to the pure g-C3 N4, the specific surface area of g-C3 N4 -MF100 is clearly increased, and the conduction band is significantly shifted up. As expected, the porous g-C3 N4 -MF100 D-A conjugated copolymer achieves the best photocatalytic hydrogen evolution (PHE) activity (3612.65 μmol h −1 g −1 ), which is over 8.87 times higher than that of pure g-C3 N4, and outperforms the majority of the previously reported g-C3 N4 -based D-A conjugated polymers and porous g-C3 N4 . In addition, the apparent quantum yield (AQY) of the porous intramolecular g-C3 N4 -MF100 D-A conjugated copolymer reaches 8.6% at 420 nm. This work provides a new design idea of effectively combining the porous and intramolecular D-A conjugated structures of g-C3 N4 to achieve a remarkably enhanced PHE activity and light utilization. Graphical abstract: A novel intramolecular g-C3 N4 -based donor-acceptor (D-A) conjugated copolymers with porous structure and larger specific surface area have been prepared by copolymerizing urea with melamine-formaldehyde (MF) resin. As expected, the g-C3 N4 -MF100 D-A conjugated copolymer achieves the best PHE activity (3612.65 μmol h −1 g −1 ), which is over 8.87 times higher than that of pure g-C3 N4, and outperforms the majority of the previously reported g-C3 N4 -based D-A conjugated polymers and porous g-C3 N4 . And the AQY of the porous intramolecular g-C3 N4 -MF100 D-A conjugated copolymer reaches 8.6% at 420 nm. Image 1 Highlights: A new porous intramolecular g-C3 N4 -MFx donor-acceptor conjugated copolymer is prepared by copolymerizing urea with MF resin. The method not only endows g-C3 N4 -MFx larger specific surface area but also possesses a porous structure. Porous intramolecular g-C3 N4 -MF100 donor-acceptor conjugated copolymer achieves the best PHE activity (3612.65 μmol h −1 g −1 ). The apparent quantum yield of g-C3 N4 -MF100 donor-acceptor conjugated copolymer is as high as 8.6% at 420 nm.