Characterizing Carbon Ring-C₃N₄ Nanosheets as a Light-Harvesting and Charge Carrier Transfer Agent: Photodegradation of Methylene Blue and Photoconversion of CO₂ to CH₄ as Case Studies

Abstract

Carbon ring−carbon nitride nanosheets (C ring -C 3 N 4 ) were synthesized by using glucose as the carbon source. The C ring -C 3 N 4 was characterized in order to check its ability in harvesting light in the visible region and transferring the charge carriers. Degradation of methylene blue (MB) after being adsorbed on the surface of the photocatalyst and also the photoreduction of CO 2 to CH 4 were studied for proving applicability of C ring -C 3 N 4 in solving pollution problem and fuel crisis. The results were compared with those of bulk C 3 N 4 . The results showed that the adsorption process was fit to the Langmuir model (with a Q max of 130 mg/g) with a kinetic of the pseudo second order (with a Q e.cal of 180 mg/g). The photodegradation rate constant of MB proved that C ring -C 3 N 4 nanosheets had a catalytic activity (0.0616/h) almost 26 times more than g-C 3 N 4 in the presence of light. At a melamine/ glucose mass ratio of 1000/50, the photoconversion rate of CO 2 to CH 4 (16.24 μmol/g•h) achieved nearly 24 times greater when compared to g-C 3 N 4 and was comparable with the photodegradation rate of MB. In the presence of light, it was observed that the reduction of carbon dioxide to methane was via a process of eight electrons which predominated over the production of carbon monoxide with a process of two electrons. The C ring -C 3 N 4 synergistically extended lifetime and photocarrier diffusion length. This photocatalyst can be effectively utilized in sustainable solar-to-fuel conversion processes as well as in environmental pollutant remediation.

Recent advances in visible-light graphitic carbon nitride (g-C3N4) photocatalysts for chemical transformations

“…Che and co-workers 106 a investigated a thermal-conjugate in-plane polymerization approach using glucose as the starting material to integrate C ring into the triazine units of g-C 3 N 4 . The synthetic route for ( C ring )-C 3 N 4 including the dehydration and polymerization process is shown in Fig.…”

Polymer Photocatalyst–Enzyme Coupled Artificial Photosynthesis System for CO2 Reduction into Formate Using Water as the Electron Donor

“…Fluorescence lifetimes of 6.2, 5.9, 5.8, and 5.2 ns were determined for C@PCN, CoSAC@PCN, CoSAC@PCN-L, and CoSAC@PCN-H, respectively (Figure S14). The evidently restrained intensity, accompanied by a shortened lifetime, indicates that the in-plane connection of the carbon ring and single Co atom with the PCN framework can effectively inhibit the recombination of photoinduced electron/hole pairs, ensuring a high photocatalytic activity caused by accelerated charge separation and migration. , Additionally, enhanced photocarrier separation was confirmed by photocurrent and electrochemical impedance spectroscopy (ESI) analysis. All samples display clear and stable responses for each switch-on and switch-off event, suggesting efficient light-initiated electronic conductivity, as well as charge separation and transfer (Figure d).…”

Preparation of bichar/layered double hydroxide@alginate aerogel as a highly efficient adsorbent for Cu2+ and Cd2+

“…According to E, the adsorption process can be determined as chemical adsorption or physical adsorption. Their equations are respectively as follows 32 :…”