One-Step Nickel Foam Assisted Synthesis of Holey G-Carbon Nitride Nanosheets for Efficient Visible-Light Photocatalytic H-2 Evolution

摘要

Graphitic carbon nitride (g-C3N4) with layered structure represents one of the most promising metal-free photocatalysts. As yet, the direct one-step synthesis of ultrathin g-C3N4 nanosheets remains a challenge. Here, few-layered holey g-C3N4 nanosheets (CNS) were fabricated by simply introducing a piece of nickel foam over the precursors during the heating process. The as-prepared CNS with unique structural advantages exhibited superior photocatalytic water splitting activity (1871.09 mu mol h(-1) g(-1)) than bulk g-C3N4 (BCN) under visible light (lambda 420 nm) (approximate to 31 fold). Its outstanding photocatalytic performance originated from the high specific surface area (240.34 m(2) g(-1)) and mesoporous structure, which endows CNS with more active sites, efficient exciton dissociation, and prolonged charge carrier lifetime. Moreover, the obvious upshift of the conduction band leads to a larger thermodynamic driving force for photocatalytic proton reduction. This methodology not only had the advantages for the direct and green synthesis of g-C3N4 nanosheets but also paved a new avenue to modify molecular structure and textural of g-C3N4 for advanced applications.