High-efficiency photocatalytic water splitting by a N-doped porous g-C3N4 nanosheet polymer photocatalyst derived from urea and N,N-dimethylformamide

Abstract

In this work, layered N-doped graphitic carbon nitride (g-C₃N₄) porous nanosheets were successfully prepared by mixing the precursor of N,N-dimethylformamide (DMF) and urea through a simple one-step thermal copolymerization method. The doped-N plays a significant role in modifying the chemical and electronic structure of g-C₃N₄, which can decrease the migration pathway of the charges and suppress the recombination of the photogenerated carriers based on experimental characterization data and the density functional theory (DFT) calculation results. Through nanostructure engineering design, the as-prepared photocatalyst exhibits promoted specific surface area and enhanced light absorption capacity. Consequently, the as-prepared N-doped porous g-C₃N₄ nanosheets yield about 14 times higher H₂ evolution rate than pristine g-C₃N₄ nanosheets under visible light irradiation. The present study provides a simple and convenient method of nanostructure engineering for the synthesis of modified g-C₃N₄ with excellent photocatalytic activity to meet the sustainable demand of energy.