Luminescent Single-Atom Eu-Coordinated Graphitic Carbon Nitride Nanosheets for Selective Sensing of Acetone and Cyclohexane

Abstract

The doping of Eu 3+ within a framework of exfoliated g-C 3 N 4 nanosheets (Eu/ nanoC 3 N 4 ) was achieved via a straightforward one-step pyrolysis process using dicyandiamide and EuCl 3 •6H 2 O as precursors in N 2 at 550 °C by the conjoint use of NH 4 Cl as a dynamic gas template. Physicochemical characterization by means of X-ray diffraction, X-ray photoelectron spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, and Eu L III -edge X-ray absorption fine structure analyses provided evidence for the generation of a single-atom Eu 3+ complex in the cavity bonded with six N atoms constructed by three heptazine units in the g-C 3 N 4 framework. Eu/nanoC 3 N 4 exhibited characteristic Eu 3+ emissions attributed to the 5 D 0 → 7 F 2 transitions, which are quickly quenched at room temperature upon exposure to particular volatile organic compounds (VOCs) with moderate adsorption energies, such as acetone and cyclohexane, as evidenced by density functional theory calculations. Fourier transform infrared analysis indicated that the sensing properties are due to a ligand−metal energy transfer mechanism between adsorbed VOC molecules and the single-atom Eu doped within the C 3 N 4 framework. The results provide insight into the utilization of single-atom Eu 3+ complexes within the framework of exfoliated g-C 3 N 4 nanosheets for the development of potential luminescent sensing materials with high sensitivity and selectivity.

Photoreduction of Carbon Dioxide to Formic Acid with Fe-Based MOFs: The Promotional Effects of Heteroatom Doping and Alloy Nanoparticle Confinement

“…Powder XRD patterns, BET surface area, DR UV–vis spectra, and PL data were acquired according to procedures described previously . Transmission electron microscopy (TEM) images were obtained with a Hitachi HF-2000 FE-TEM operated at 200 kV.…”

“…Powder XRD patterns, BET surface area, DR UV−vis spectra, and PL data were acquired according to procedures described previously. 34 Transmission electron microscopy (TEM) images were obtained with a Hitachi HF-2000 FE-TEM operated at 200 kV. The metal content in the samples was determined by inductively coupled plasma atomic emission spectroscopy (ICP-ES) measurements with a Nippon Jarrell-Ash ICAP-575 Mark II instrument.…”

Progress and Perspectives of Single‐Atom Catalysts for Gas Sensing

“…Reproduced with permission. [115] Copyright 2020, American Chemical Society. d) Schematic illustration of the synthesis of Ni SACs/N-C. e) Data are represented as current response recorded with three different modified electrodes.…”

On the electronic properties and catalytic activity of MoS2–C3N4 materials prepared by one-pot reaction

“…Notably, ammonium thiomolybdate is well soluble in molten urea, forming a dark-red solution at the temperatures below 200 °C. It appears however that reaction at higher temperatures does not allow incorporation of any considerable amount of single-atomic Mo species into the carbon nitride framework (as it happens for many divalent and trivalent cations of metals 46,47 ), but leads to quantitative precipitation of MoS2. Perhaps, unlike the cationic species that tend to be coordinated with nitrogen lone electronic pairs of the carbon nitride structure, the MoS4 2anion has no affinity towards nitrogen in the C3N4 cavities.…”