K⁺ Ion-Doped Mixed Carbon Nitride: A Daylight-Driven Photocatalyst and Luminophore for Enhanced Chemiluminescence

Abstract

Photocatalytic production of reactive oxygen species from O 2 at the interface of the photocatalyst is significant to convert luminous energy like daylight into chemical energy and could be momentous for a reactive oxygen species-based chemiluminescence system. Herein, we synthesized a novel K + ion-doped tri-s-triazine/ triazine mixed carbon nitride (MCN), in which K + ions were intercalated into the layers in a bridging manner. After a mild daylight treatment for 30 min, the MCN suspension could produce long-lifetime reactive oxygen species and further directly produce intense and stable chemiluminescence emission in the presence of luminol. In particular, the chemiluminescence intensity was 780 times that of H 2 O 2 −luminol, and MCN could be recycled several times in the chemiluminescence system. The mechanism results revealed a large number of reactive oxygen species that were generated from O 2 on the surface of MCN through a temperate photocatalytic process. In the theoretical calculation, the charge density of N interacting with K + ions was significantly more negative than that at the corresponding position in graphitic carbon nitride, which was beneficial to the adsorption and activation of oxygen, and the narrower band gap suggested that the doping of K + ions was conducive to the intramolecular charge transfer interaction. Then, the long-lifetime reactive oxygen species triggered the conversion of luminol into an excited-state intermediate, which further transferred energy to MCN, producing strong chemiluminescence emission. The K + ion-doped MCN might conduct as an efficient photocatalyst for reactive oxygen species generation, recyclable catalysts, and luminophores in the photoinduced chemiluminescence system.

Europium-Functionalized Graphitic Carbon Nitride for Efficient Chemiluminescence Detection of Singlet Oxygen

“…The high-resolution C 1s and N 1s XPS spectra provided further insights into the surface state (Figure C,D). The C 1s spectra of Eu-CNNPs exhibited three peaks at 287.9, 286.1, and 284.8 eV, assigned to N–CN, C–NH x , and C–C/CC, respectively. The N–CN content (287.9 eV) decreased from 56.37 to 25.89%, while the C–NH x content (286.1 eV) increased from 6.44 to 7.20% and the C–C/CC content (284.8 eV) increased from 37.19 to 66.91% in Eu-CNNPs.…”

Bimetallic CoMoO4 Nanozymes Enhanced Luminol Chemiluminescence for the Detection of Dopamine

“…Offering simplicity in equipment, high sensitivity, and a broad linear range, CL has found extensive applications in the detection of ions and small molecules, immunoassay, imaging, nucleic acid detection, etc. Luminol, recognized as a typical lumiphore, has gained popularity due to its water solubility, stability, and cost-effectiveness. , However, the low CL efficiency of the classical luminol/hydrogen peroxide (H 2 O 2 ) system has greatly limited their wide development in analytical applications. Therefore, a lot of efforts have been focused on the exploration of new coreactants and the synthesis of functional materials with catalytic properties to improve the CL efficiency. , …”

Potassium Molten Salt-Mediated In Situ Structural Reconstruction of a Carbon Nitride Photocatalyst

“…Until now, a plethora of strategies have been employed to alter the photophysical properties of bulk PCN, which include molecular-scale doping, heterostructure design, nanostructure engineering, crystallinity modulation, and structural alternation. Subsequently, highly crystalline PCN-type materials known as poly­(triazine imide) (PTI), poly­(heptazine imide) (PHI), and mixed PHI/PTI are synthesized by eutectic salt mixtures and have shown promising photocatalytic activity. − However, a high degree of crystallinity does not necessarily signify a greater photocatalytic activity, and most of the reports postulate that surface dangling bonds or defects are the real reaction active sites for PCN-related photocatalysts. − Hence, increasing the number of surface-active sites is a strategic approach to level up the photocatalytic activity of PCN-based materials.…”