Porous graphitic carbon nitride nanosheets prepared under self-producing atmosphere for highly improved photocatalytic activity

[Display omitted] •We introduced pyrolysis-generated self-producing atmosphere to induce the process of condensation.•Porous gC3N4 with abundant amino groups was fabricated simply.•We provide a new simple and effective strategy for improving the intrinsic electronic structures and photocatalytic performance of gC3N4. The reaction atmosphere employed in graphitic carbon nitride (gC3N4) synthesis can play an important role in modifying the electronic structure and the properties of photoexcited charge carriers and consequently the photocatalytic activity of semiconductor photocatalysts. By controlling the entrance of N2 in the preparation of gC3N4, we introduced pyrolysis-generated self-producing atmosphere. Under the homogeneous self-producing atmosphere and without any other additives, we fabricated porous gC3N4 with more uncondensed amino groups. These formed pores endow gC3N4 nanosheets with more exposed active edges and cross-plane diffusion channels that greatly speed up mass and charge carrier transfer. Furthermore, the uncondensed amino groups within the structure could promote the dispersion behavior of samples in water and induce the structure distortion of gC3N4 layers through the strong hydrogen bonding interactions between layers and thus decease the distance of interlayers. Enhanced photocatalytic activity is seen as well from a drastic increase in the degradation of rhodamine B (RhB) dye. This work provides a simple and efficient strategy for fabricating porous texture and realizing the tunable structure distortion of g-C3N4 layers to adjust its electronic structure and photocatalysis.