Brønsted base site engineering of graphitic carbon nitride for enhanced photocatalytic activity. Issue 36 (31st August 2017)

• Record Type: Journal Article
• Authors: Wang, Xue Lu; Fang, Wen Qi; Liu, Wenqing; Jia, Yi; Jing, Dengwei; Wang, Yun; Yang, Ling-Yun; Gong, Xue-Qing; Yao, Ye-Feng; Yang, Hua Gui; Yao, Xiangdong
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 36(2017)
• Page Start: 19227
• Page End: 19236
• Publication Date: 2017-08-31
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta06602c
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Through the combination of a HPH method and 2D 15 N SSNMR spectroscopy, the Brønsted base sites of g-C3 N4 can be tuned and identified. Abstract : Graphitic carbon nitride (g-C3 N4 ) is a promising two-dimensional polymeric photocatalyst in the field of solar energy conversion. In the past few years many modifications of g-C3 N4 have been studied extensively; however, the difficulty in obtaining detailed structural information both on its intrinsic covalent interactions and surrounding bonding environments largely restricts the rational design and development of inherent structure-controlled g-C3 N4 based photocatalysts and fundamental understanding of their mechanistic operations. Herein, we demonstrate a high-pressure hydrogenation treatment method for g-C3 N4 and introduce 1D 13 C and 15 N and 2D 15 N Radio Frequency-driven Dipolar Recoupling (RFDR) solid-state nuclear magnetic resonance spectroscopy for identifying the structural information and surrounding hydrogen-bonding environment of treated g-C3 N4 samples. The surface Brønsted base sites of g-C3 N4 samples can be tuned systematically through changing the treatment conditions. We find that the terminal isolated –NH2 and the hydrogenated nitrogen species in treated g-C3 N4 samples seem to be the origin of their improved activities for photocatalytic hydrogen evolution and favor the enhancement of light harvesting and carrier transport. The as-prepared HCN400-4-2 sample treated at a pressure of 4 MPa and a temperature of 400 °C for 2 h in a hydrogen atmosphere displays the highest H2 evolution reaction (HER) activity, which is over 26 times higher than that of pristine g-C3 N4 .