Asymmetric structure engineering of polymeric carbon nitride for visible-light-driven reduction reactions

• Published in: Nano energy 2021-09, Vol.87, p.106168, Article 106168
• Main Authors: Luo, Wei, Li, Yongli, Wang, Jinshu, Liu, Jingchao, Zhang, Nan, Zhao, Mengdi, Wu, Junshu, Zhou, Wenyuan, Wang, Lianzhou
• Format: Article
• Language: English
• Subjects: Aromatization; Asymmetric structure; Gas-solid grafting reaction; Photocatalytic reductions; Terminal blocking
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2021.106168

The photocatalytic activity of polymeric carbon nitride (g-C3N4) strongly depends on its electronic structure which is highly sensitive to the preparation methods. To design the photocatalysts with efficient charge separation and transfer property, here we report a new ethylenediamine (EDA) induced gas-solid grafting method which enables the asymmetric modification of g-C3N4 featuring the aromatization at the terminal of melon motifs. The obtained terminal-aromatized g-C3N4 (Ar-C3N4) exhibits an improved visible-light-driven photocatalytic activity in versatile two-electron reduction reactions, outperforming the pristine g-C3N4 by 15.4 and 6.6 folds respectively in hydrogen evolution and hydrogen peroxide production. Theoretical and experimental results demonstrate the intensified asymmetry of π-electron distribution in the resulting material, which provides significantly improved driving force to guide the efficient separation of photogenerated e-h pairs and enhance the charge carrier mobility compared to its symmetric counterpart. [Display omitted] ●Asymmetric modification of g-C3N4 is developed via a new EDA involved gas-solid grafting process.●The structure demonstrates lopsided arrangement of melon-based motifs featuring aromatization of terminal groups.●Intensified asymmetric electron distribution is constructed.●Significantly enhanced photocatalytic two-electron reductions are obtained.