Dimensional transformation and morphological control of graphitic carbon nitride from water-based supramolecular assembly for photocatalytic hydrogen evolution: from 3D to 2D and 1D nanostructures

• Published in: Applied catalysis. B, Environmental Vol. 254; pp. 321 - 328
• Main Authors: Zhou, Bing-Xin, Ding, Shuang-Shuang, Zhang, Bei-Jing, Xu, Lei, Chen, Ruo-Shi, Luo, Leng, Huang, Wei-Qing, Xie, Zhong, Pan, Anlian, Huang, Gui-Fang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.10.2019; Elsevier BV
• Subjects: Carbon; Carbon nitride; Cyanuric acid; Genetic transformation; Heat treatment; Heat treatments; Hydrogen evolution; Irradiation; Light irradiation; Mathematical morphology; Melamine; Morphological control; Morphology; Nanomaterials; Nanotechnology; Photocatalysis; Polymers; Precursors; Radiation; Supramolecular; Thickness; Supramolecular; Morphological control; Photocatalysis; Hydrogen evolution; Carbon nitride
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.05.015

[Display omitted] •We have developed a novel strategy for construction of 2D nanosheets, 1D nanotubes, and porous 3D loofah-like architectures of g-C3N4.•The resulting ultrathin 2D g-C3N4 nanosheets have a high yield of ∼10 wt%, a small thickness (1.6 nm), and a large surface area (208.8 m2 g−1).•The ultrathin 2D g-C3N4 nanosheets exhibit high hydrogen evolution rate by 17.3 times than bulk g-C3N4 under visible light irradiation.•The proposed strategy is expected to broaden our horizons in designing highly-active photocatalysts for energy-related applications. Geometric dimensionality and morphology largely affect the properties and functionalities of materials; however, simultaneously regulating them to realize synergic effects is a formidable scientific and technological challenge. Here we demonstrate an effective strategy to control the dimensionality and morphology of graphitic carbon nitride (g-C3N4) through heat treatment the melamine-cyanuric acid supramolecular precursors formed in water as a “green” solvent. By varying heat treatments, the three-dimensional (3D) hexagonal prism precursors could be transformed to 3D g-C3N4 loofah-like (CNl) architectures, ultrathin two-dimensional (2D) g-C3N4 nanosheets (CNs), and ordered one-dimensional (1D) g-C3N4 nanotube (CNt) array, respectively. The adsorbed melamine molecules on the surface of precursor and atmosphere in the transformation process, play a key role in determining the morphology of products. The resulting ultrathin 2D CNs have a porous structure, a small thickness (1.6 nm), a large surface area (208.8 m2·g−1), and high conductivity, thus exhibiting higher hydrogen evolution rate (23.9 μmol h−1) by 17.3 times than the bulk g-C3N4 (CN) under visible light irradiation. This strategy results in high-quality, ultrathin CNs at yields of ∼10 wt% from raw material, much higher than those of previous reports (∼6 wt% from bulk CN). This work not only enriches our understanding of the relationship between geometric dimensionality, morphology and properties of photocatalytic nanomaterials, but also could be potentially useful for the design and growth of 1D or 2D flexible polymers for energy-related applications and beyond.