Asymmetric Structure Engineering of Polymeric Carbon Nitride for Visible-light-driven Reduction Reactions

Abstract 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.