Confined Synthesis of Carbon Nitride in a Layered Host Matrix with Unprecedented Solid‐State Quantum Yield and Stability

Abstract

Fluorescent carbon nanomaterials have drawn tremendous attention for their intriguing optical performances, but their employment in solid-state luminescent devices is rather limited as a result of aggregation-induced photoluminescence quenching. Herein, ultrathin carbon nitride (CN) is synthesized within the 2D confined region of layered double hydroxide (LDH) via triggering the interlayer condensation reaction of citric acid and urea. The resulting CN/LDH phosphor emits strong cyan light under UV-light irradiation with an absolute solid-state quantum yield (SSQY) of 95.9 ± 2.2%, which is, to the best of our knowledge, the highest value of carbon-based fluorescent materials ever reported. Furthermore, it exhibits a strong luminescence stability toward temperature, environmental pH, and photocorrosion. Both experimental studies and theoretical calculations reveal that the host-guest interactions between the rigid LDH matrix and interlayer carbon nitride give the predominant contribution to the unprecedented SSQY and stability. In addition, prospective applications of the CN/LDH material are demonstrated in both white light-emitting diodes and upconversion fluorescence imaging of cancer cells.

Confined Synthesis of 2D Nanostructured Materials toward Electrocatalysis

“…How to construct 2D carbon nitride is of high importance to enlarge the surface area and optimize the active sites, so as to achieve performance enhancement. Recently, Wei and co‐workers successfully synthesized ultrathin carbon nitride in LDHs via space‐confined synthesis method ( Figure 6 a) 109. Citric acid (CA)‐intercalated MgAl‐LDH nanoplatelets (CA/LDH, diameter of ≈60 nm; Figure 6b) were first prepared through separate nucleation and ageing steps.…”

“…SEM images of b) CA/LDH and c) CN/LDH; the insets show the photographs of CA/LDH and CN/LDH under daylight. Reproduced with permission 109. Copyright 2018, John Wiley & Sons, Inc. d) Schematic representation for the space‐confined synthesis of PCHs.…”

Triamterene‐Grafted Graphitic Carbon Nitride with Electronic Potential Redistribution for Efficient Photocatalytic Hydrogen Evolution

“…The O1s peak can be attributed to adsorbed oxygen species, such as water and oxygen. [31,32] The high-resolution C1ss pectra (Figure 2b)can be divided into two main peaks with binding energies of 284.8 and 288.3 eV,c orresponding to the sp 2 carbon atoms in the C=Ca nd NÀC=Nm oieties, respectively.A ne xtra, low-intensity peak in the C1ss pectrum of UTP-2 at ab inding energy of 286.2 eV comes from the CÀNH x (x = 1, 2) speciesa t the edges of the heptazine unites, [33] which suggestst hat copolymerization leads to an increase in the content of terminal C=NÀH. In addition, the microstructure of UTP-2 comprises smaller nanosheets and ad istorted framework ( Figure 4), which indicates that copolymerization leads to more terminal ÀNH 2 groups.…”

Recent advancements in two‐dimensional nanomaterials for drug delivery

“…Chen and coworkers prepared mesopore‐coated 2D Nb 2 C MXenes, which exhibited an excellent photothermal conversion of 28.6% in the 1,064 nm near infrared (NIR)‐II biowindow for enhanced PTT. In another work, Liu and coworkers demonstrated the surface functionalization of superparamagnetic iron oxide on Ta 4 C 3 (D. Liu, Lin, Tang, et al, ; Z. Liu, Lin, Zhao, et al, ; C. Liu, Qin, et al, ; W. Liu, Xu, et al, ). This MXene nanosystem was reported to have great MRI guided PTT for breast‐cancer therapy.…”