Graphene‐Like Carbon Nitride Nanosheets for Improved Photocatalytic Activities

Abstract

Abstract“Graphitic” (g)‐C3N4 with a layered structure has the potential of forming graphene‐like nanosheets with unusual physicochemical properties due to weak van der Waals forces between layers. Herein is shown that g‐C3N4 nanosheets with a thickness of around 2 nm can be easily obtained by a simple top‐down strategy, namely, thermal oxidation etching of bulk g‐C3N4 in air. Compared to the bulk g‐C3N4, the highly anisotropic 2D‐nanosheets possess a high specific surface area of 306 m2 g−1, a larger bandgap (by 0.2 eV), improved electron transport ability along the in‐plane direction, and increased lifetime of photoexcited charge carriers because of the quantum confinement effect. As a consequence, the photocatalytic activities of g‐C3N4 nanosheets have been remarkably improved in terms of •OH radical generation and photocatalytic hydrogen evolution.

Hydrogenated Defects in Graphitic Carbon Nitride Nanosheets for Improved Photocatalytic Hydrogen Evolution

“…Indeed, experiments with different wavelength cutoffs show that the low rate of H 2 evolution observed for g-C 3 N 4 -2A is due to the large band gap of the nanosheet structure (Figure S5). Here the result is contrary to the reported results that nanosheet structured carbon nitride shows higher activity compared to bulk carbon nitrides . The difference might be due to the experimental variation as a 400 nm cutoff filter was used in the previously reported experiments .…”

Sheets Copper‐Cobalt Graphitic Carbon Nitride Dual Single‐Atom Catalysts for the Epoxidation of Styrene

“…The broad absorption band in the range of 3600–3000 cm −1 indicates the presence of N−H bonds and O−H, which are originated from uncondensed terminal amino groups and −OH groups for adsorbed water. These results are highly consistent with the previously reported infrared characteristic absorption peaks of graphitic carbon nitride [17b,22] . S−Cu/Co‐g‐C 3 N 4 ‐1 : 1 has a significantly higher cyano peak than other samples.…”

Porous carbon nitride nanosheets for enhanced photocatalytic activities

“…S2C and S2D † show that the typical thickness of CNs is around 2-3 nm, corresponding to 5-8 C-N layers. This is similar to those reported in the literature (1.65-2.62 nm, 10 2 nm, 11 2.5 nm 24 ). Though the same exfoliation conditions were applied to CN and PCN, the thickness of PCNs is roughly twice of that of CNs.…”