Facile transformation of low cost melamine–oxalic acid into porous graphitic carbon nitride nanosheets with high visible-light photocatalytic performance

Abstract

Here, we report a simple, robust and large-quantity synthetic pathway to form porous graphitic carbon nitride nanosheet structures, using a long strip-like structure of melamine–oxalic acid (MO) as a starting product. The addition of oxalic acid can influence the thermal condensation model and inhibit grain growth of g-C₃N₄. Meanwhile, the synergism of MO precursor and specific heating process can effectively adjust the porosity and number of layers. The synthesized porous g-C₃N₄ nanosheets possess large specific surface areas (203 m² g⁻¹), a widened band gap 2.98 eV, and improved electron transport ability, exhibit high photocatalytic activities as much as 8 times than bulk g-C₃N₄ for the photodegradation of gas pollute under visible light (λ > 420 nm). This work shows a significant progress for low-cost fabrication of high quality porous 2D g-C₃N₄ with excellence photocatalytic activity.