Ternary Synergism: Synthesis of S, C Co-doped g-C3N4 hexagonal ultra-thin tubular composite photocatalyst for efficient visible-light-driven photocatalytic hydrogen production

Here, we demonstrate a new type of S and C co-doped g-C3N4 hexagonal ultra-thin tubular composite photocatalyst with extraordinary photocatalytic activity toward H2 production from H2O with visible light irradiation. The S and C co-doped g-C3N4 hexagonal ultra-thin tubular composite photocatalyst was prepared through a precursor calcinating process at 520 °C in a nitrogen atmosphere. The precursor was obtained through a supramolecular self-assembly strategy using melamine and thiolactic acid as raw materials by a crosslinking process of sulfhydryl and carboxyl groups. Benefiting from the synergetic effects of elements doping and the ultra-thin tubular morphology, the obtained S and C co-doped g-C3N4 hexagonal ultra-thin tubular composite photocatalyst exhibits a highly efficient photocatalytic activity toward H2 production from H2O with the irradiation of visible light, which is 24 times higher than that of the pristine g-C3N4. The optimized apparent quantum yield was demonstrated to be around 9.56 %. A possible photocatalytic mechanism relating to H2 evolution from H2O with visible light irradiation concerning the prepared S and C co-doped g-C3N4 hexagonal ultra-thin tubular composite photocatalyst was proposed. The current study might provide valuable insights for the design and synthesis of highly efficient photocatalysts for hydrogen production using solar energy.