ACS Appl Mater Interfaces. 2018 Jun 20;10(24):20521-20529. doi: 10.1021/acsami.8b04783. Epub 2018 Jun 11.
Graphitic carbon nitride (g-CN) with layered structure represents one of the most promising metal-free photocatalysts. As yet, the direct one-step synthesis of ultrathin g-CN nanosheets remains a challenge. Here, few-layered holey g-CN 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 μmol h g) than bulk g-CN (BCN) under visible light (λ > 420 nm) (≈31 fold). Its outstanding photocatalytic performance originated from the high specific surface area (240.34 m g) 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-CN nanosheets but also paved a new avenue to modify molecular structure and textural of g-CN for advanced applications.
石墨相氮化碳(g-CN)具有层状结构,是最有前途的无金属光催化剂之一。然而,将其直接一步合成超薄的 g-CN 纳米片仍然是一个挑战。在这里,通过在加热过程中将一块镍泡沫置于前体上,简单地制备了具有层状多孔结构的 g-CN 纳米片(CNS)。与体相 g-CN(BCN)相比,具有独特结构优势的所制备的 CNS 在可见光(λ>420nm)下表现出优异的光催化水分解活性(1871.09 μmol h g)(约 31 倍)。其优异的光催化性能源于高比表面积(240.34 m g)和介孔结构,这赋予了 CNS 更多的活性位点、有效的激子解离和延长的载流子寿命。此外,导带的明显上移导致光催化质子还原的热力学驱动力更大。这种方法不仅具有直接、绿色合成 g-CN 纳米片的优势,而且为进一步应用提供了修饰 g-CN 分子结构和质地的新途径。