One-step synthesis of g-C3N4 hierarchical porous structure nanosheets with dramatic ultraviolet light photocatalytic activity

Graphitic carbon nitride (g-C3N4) nanosheets with hierarchical porous structure were synthesized via one-step thermal condensation-oxidation process. The microstructure of g-C3N4 was characterized to explain the dramatic ultraviolet light photocatalytic activity. The results showed that g-C3N4 hierarchical aggregates were assembled by nanosheets with a length of 1-2 μm and a thickness of 20-30 nm. And the N2-adsorption/desorption isotherms further informed the presence of fissure form mesoporous structure. An enhanced photocurrent of 37.2 μA was obtained, which is almost 5 times higher than that of P-25. Besides, the g-C3N4 nanosheets displayed the degradation of Rhodamine B with 99.4% removal efficiency in only 9 min. Such highly photocatalytic activity could be attributed to the nano platelet morphology which improves electron transport ability along the in-plane direction. In addition, the hierarchical porous structure adapted a wider band gap of C3N4. Therefore, the photoinduced electron-hole pairs have a stronger oxidation-reduction potential for photocatalysis.