Photocatalytic H₂-Evolution Performance of Graphene Quantum Dots/g-C₃N₄ Hybrid Photocatalyst

In this work, we reported a systematic study of the relationship between photocatalytic properties of hydrogen evolution and structures and morphologies of g-C₃N₄ prepared by different precursors (urea, melamine and dicyandiamide). The photocatalytic performances of H₂ production were affected by the method and degree of polymerization, the degree of protonation, and the morphology of g-C₃N₄ prepared by different precursors. Furthermore, a novel metal-free N-GQDs/g-C₃N₄ catalyst was designed and synthesized, which shown much better photocatalytic activity for H₂ evolution from water splitting than that of g-C₃N₄ due to the unique and multiple roles of N-GQDs. A mechanism was put forth to explain the roles of N-GQDs and the detailed enhancement of photocatalytic performance of the N-GQDs/g-C₃N₄.