Functional groups to modify g-C3N4 for improved photocatalytic activity of hydrogen evolution from water splitting

• Published in: Chinese chemical letters Vol. 31; no. 6; pp. 1648 - 1653
• Main Authors: Yu, Fan, Wang, Laichun, Xing, Qiuju, Wang, Dengke, Jiang, Xunheng, Li, Guangchao, Zheng, Anmin, Ai, Fanrong, Zou, Jian-Ping
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2020; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China%State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China%School of Mechanical&Electronic Engineering, Nanchang University, Nanchang 330031, China
• Subjects: Functional groups; Graphitic carbon nitride; Hydrogen evolution; Photocatalysis; Synthesis; Synthesis; Hydrogen evolution; Photocatalysis; Functional groups; Graphitic carbon nitride
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2019.08.020

A new strategy was proposed to improve photocatalytic Hydrogen evolution of g-C3N4via modification of functional groups of NCH. [Display omitted] Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride (g-C3N4). Herein, g-C3N4 with yellow (Y-GCN) and brown (C-GCN) were prepared by using the fresh urea and the urea kept for five years, respectively, for the first time. Experimental results show that the H2 production rate of the C-GCN is 39.06 μmol/h, which is about 5 times of the Y-GCN. Meantime, in terms of apparent quantum efficiency (AQE) at 420 nm, C-GCN has a value of 6.3% and nearly 7.3 times higher than that of Y-GCN (0.86%). The results of XRD, IR, DRS, and NMR show, different from Y-GCN, a new kind of functional group of NCH was firstly in-situ introduced into the C-GCN, resulting in good visible light absorption, and then markedly improving the photocatalytic performance. DFT calculation also confirms the effect of the NCH group band structure of g-C3N4. Furthermore, XPS results demonstrate that the existence of NCH groups in C-GCN results in tight interaction between C-GCN and Pt nanoparticles, and then improves the charge separation and photocatalytic performance. The present work demonstrates a good example of “defect engineering” to modify the intrinsic molecular structure of g-C3N4 and provides a new avenue to enhance the photocatalytic activity of g-C3N4via facile and environmental-friendly method.