Promotion of photocatalytic hydrogen evolution induced by graphitic carbon nitride transformation from 2D flakes to 1D nanowires

In this contribution, a sustainable approach to fabricate one-dimensional (1D) graphitic carbon nitride (gCN) for photocatalytic hydrogen generation is reported. The strategy was based on L-ascorbic acid (LAA) modification of two-dimensional (2D) gCN leading to the formation of a 1D structure. The resultant gCN_1D exhibits an increased photocatalytic hydrogen generation rate of ∼18-fold and 4-fold with respect to 2D bulk-gCN and exfoliated gCN (ex-gCN), respectively. The photocatalytic mechanism of hydrogen evolution from water splitting was proposed based on a detailed physiochemical investigation of the catalyst prior and after the process. The enhanced photocatalytic H2 generation of the gCN_1D is achieved due to enhanced light harvesting, the better position of valance and conduction bands, higher porosity, faster transfer and charge separation of photogenerated carriers, and lower recombination rate resulting from 1D nanostructure. Additionally, promoted stability is assigned to the formation of an additional phase of the CN4O8 during the photocatalytic process.