Harnessing Photoluminescent Properties of Carbon Nitride Nanosheets in a Hierarchical Matrix

Abstract

Rapid screening of polycyclic aromatic hydrocarbons (PAHs), a large class of toxic and carcinogenic compounds, is highly desirable for environmental and food safety. In principle, a photoluminescent (PL) assay is a potential route, but demands highly efficient and stable, low cost, and environment-friendly photoactive materials. 2D carbon nitride nanosheets (CNNS) that have triggered increasing interest may meet all these requirements. However, conventional applications of CNNS are restricted in aqueous solution, in which the long-term dispersibility is difficult to be addressed. Here, the harnessing of unique PL properties of CNNS is reported by dispersing them in a hierarchical polymeric matrix, driven by electrostatic interactions. Such a configuration not only enables a solid-state host to perpetually maintain homogeneous dispersibility of CNNS but also processes free channels for sufficient mass transfer. Moreover, the nanohybrid inherits the unique PL properties of CNNS. Further using β-CD as the molecular recognition unit, an economic, highly selective and sensitive paper-based PL sensor for PAHs is constructed via an inner-filter effect. This work opens a new avenue in harnessing unique PL properties of CNNS in solid state with superior stability for a variety of potential sensing applications, especially for point-of-care testing and/or in developing countries.

Upgrading poly(styrene‐co‐divinylbenzene) beads: Incorporation of organomodified metal‐free semiconductor graphitic carbon nitride through suspension photopolymerization to generate photoactive resins

“…Very recent review by Zhang and colleagues nicely describes the synthesis of diverse carbon nitride materials and their corresponding electronic properties and applications, thus underlining the emergent interest on g‐CN family 14 . For instance, tailored g‐CN nanosheets from 2D layers to 3D network by reversible assembly resulted in a functional hydrogel network exhibiting high selectivity for dye extraction 15 . g‐CN was also described as a radical photoinitiator for radical polymerization reactions by a photoredox initiation mechanism 16–18 .…”

C2N: A Class of Covalent Frameworks with Unique Properties

“…[ 20 ] These CN materials can be prepared by simple polycondensation of various organic molecular monomers, and their optical, electronic properties, and structural parameters could be easily controlled by simply modifying the synthetic procedures or hybridizing with other nanostructures. Among these CNs, the most studied C 3 N 4 exhibits semiconducting properties and has gained significant importance in a wide range of application possibilities such as heterogeneous photocatalysis, [ 12 ] water molecules actuators, [ 21,22 ] optoelectronic sensing, [ 23–25 ] biosensing/bioimaging, [ 26,27 ] and photoelectrochemical conversion. [ 28,29 ] The successful dissolution of C 3 N 4 allowed the homogeneous CN photocatalyst.…”

Highly Selective and Stable Zn (II)‐Based Metal–Organic Frameworks for the Detections of Tetracycline Antibiotic and Acetone in Aqueous System

“…Wherein, I 0 and I are the initial fluorescence intensity and the fluorescence intensity after the analyte was added, [ Q ] is the molar concentration of the analyte, and K sv is the Stern‐Volmer (SV) constant. [ 34 ] As shown in Figure 4, the SV plot of 1 exhibits good linear correlation in a range of 0 to 75 μM ( R 2 = 0.9913), while 2 also exhibits a good linear relationship in the low concentration range of 0 to 10 μM ( R 2 = 0.9916) but to deviate linearly with increasing concentration. The cause of the nonlinearity of the SV plot at high concentrations may be the self‐absorption or energy transfer process.…”