Nitrogen-rich graphitic carbon nitride: Controllable nanosheet-like morphology, enhanced visible light absorption and superior photocatalytic performance

Abstract

Herein, we reported the synthesis of nitrogen-rich graphitic carbon nitride nanosheets (NRCNNS) material by an NH4Cl assisted chemical blowing approach, where the released gas from the decomposition of NH4Cl prohibited the further polymerization of CN framework and separated the CN layers. A typical two-dimensional morphology with high aspect-ratio was demonstrated by scanning electron microscopy and transmission electron microscopy observation, and the excess amino group on the skeleton was proved by Fourier transform infrared and X-ray photoelectron spectra technologies. Different from the spectral blue-shift in other carbon nitride nanosheets, an enhanced absorption in visible light region was achieved in our NRCNNS due to the N,O-doping level in the band gap. The optimal NRCNNS material with an NH4Cl/melamine mass ratio of 4.0 exhibited a promoted activity (5 times higher than that of the bulky carbon nitride) and reusability for degradation of organic dye under visible light irradiation. Moreover, a possible mechanism was proposed based on the results of valence band spectra and the quenching experiments of active species.