Tailored Graphitic Carbon Nitride Nanostructures: Synthesis, Modification, and Sensing Applications

Abstract

donating-driven property (e.g., catalysis and strong affinity to Lewis acid). These unique properties motivated huge activity in sensing applications of g-CN, indicating by the growing collection of publications concerning g-CN-based sensors, as displayed in Figure 3.This article reviews state-of-the-art sensing applications of nanostructured g-CN. We begin with a highlight of the diverse micro/nanostructures and nanocomposites of g-CN that are suitable for sensing applications and summarize the known signaling modes and sensing mechanisms. This is followed by a highlight of several interesting sensing examples. Finally, we also discuss new frontiers in the use of g-CN for sensing applications and identify existing challenges.

Graphitic Carbon Nitride Nanosheets as Co‐reactants for Tris(2,2′‐bipyridine)ruthenium(II) Electrochemiluminescence

“…In the past decade, diverse coreactants have been developed mainly including ammonia gas, [8] biomolecules such as 2-(dibutylamino)ethanol and Lcysteine, [9][10][11] and nanomaterials like carbon nanodots and boron nitride quantum dots. [21][22][23][24] Among various nanostructures, g-CN nanosheets (CNNS) with anisotropic two-dimensional geometric morphology exhibit unique features, such as a highly opened-up flat structure with an enlarged surface area, reduced thickness with intrinsic semiconductive property but enhanced electron mobility, and well film-forming capability. [17][18][19] Graphitic carbon nitride (g-CN) is a semiconductor polymer with layer structure whereby intralayer is composed of triazine or tri-s-triazine units connected aromatic planes and interlayer is assembled by Van der Waals force and hydrogen bond.…”

“…[6] Ru(bpy) 3 2 + ECL occurs by means of two pathways: ion annihilation and co-reactant. [21][22][23][24] Among various nanostructures, g-CN nanosheets (CNNS) with anisotropic two-dimensional geometric morphology exhibit unique features, such as a highly opened-up flat structure with an enlarged surface area, reduced thickness with intrinsic semiconductive property but enhanced electron mobility, and well film-forming capability. Ru(bpy) 3 2 + /tripropylamine (TrPA) co-reactant system is currently the most widely used Ru(bpy) 3 2 + ECL system.…”

“…However, using TrPA as co-reactant for Ru(bpy) 3 2 + ECL is unsatisfactory due to its high volatility, poor aqueous solubility, high biotoxicity, and strong ECL background. [21][22][23][24] Among various nanostructures, g-CN nanosheets (CNNS) with anisotropic two-dimensional geometric morphology exhibit unique features, such as a highly opened-up flat structure with an enlarged surface area, reduced thickness with intrinsic semiconductive property but enhanced electron mobility, and well film-forming capability. In the past decade, diverse coreactants have been developed mainly including ammonia gas, [8] biomolecules such as 2-(dibutylamino)ethanol and Lcysteine, [9][10][11] and nanomaterials like carbon nanodots and boron nitride quantum dots.…”

Tris(2,2’‐bipyridyl)ruthenium(II)‐Nanomaterial Co‐Reactant Electrochemiluminescence

“…Graphitic carbon nitride (g-CN) nanomaterials are layered structural semiconductor polymers with triazine or tri-s-triazine units connected aromatic plane in each layer and inherent primary and tertiary amine groups on the surface. [43][44][45][46][47][48] Recently, our group studied ECL responses of Ru(bpy) 3 2 + at glassy carbon electrode (GCE) modified with and without graphitic carbon nitride nanosheets (CNNS), and found that not only the inherent amine groups on the surface of CNNS but also the electrochemically generated charge carriers in CNNS involved in anodic Ru(bpy) 3 2 + ECL. [32] As shown in Figure 4, the Ru(bpy) 3 2 + / CNNS co-reactant ECL occurs by i) the "oxidative-reduction" pathway where Ru(bpy) 3 2 + * is generated via the interaction between Ru(bpy) 3 3 + and the chemical/electrochemical oxidation product of the amine groups on the CNNS surface, and ii) the "reductive-reduction" pathway where Ru(bpy) 3 2 + * is generated via the chemical reaction between Ru(bpy) 3 3 + and the electroreduction product of CNNS.…”

Covalent Functionalization of Carbon Nitride Frameworks through Cross‐Coupling Reactions

“…Two‐dimensional (2D) carbon nitride (CN) based semiconductors possess great promise in various fields as solar fuels production, bio‐imaging, sensing, light‐emitting diodes and solar cells due to their unique electronic, optical, and structural properties, as well as to their low price, environmentally friendly nature, and high stability to oxidation and harsh chemical condition . The synthesis of CN frameworks usually relies on the condensation of nitrogen‐rich organic molecules, such as urea, dicyandiamide, or melamine, at elevated temperatures .…”