Graphitic Carbon Nitride Codoped with Sulfur and Yttrium for Efficient Visible-Light Photocatalytic Performance

Abstract

The correlation of electronic band structure and photocatalytic performance of graphitic carbon nitride (g-C3N4) provides important perspectives for understanding the catalytic mechanism and developing efficient catalysts. Herein, sulfur and yttrium codoped graphite carbon nitride (Y/S–CN) was prepared by a facile calcination process of melamine, 2-thiobarbituric acid, and yttrium nitrate hexahydrate at elevated temperatures. The hydrogen evolution rate of the optimal 0.01Y/S–CN photocatalyst reached 19.2 μmol/h, which was about 16 times that of pure CN and 3.51 times that of S–CN. This outstanding photocatalytic performance originates from that doping. Sulfur and yttrium into the g-C3N4 lattice improved the separation and migration of electron–hole pairs, narrowed the band gap, and increased visible light harvest. DFT calculation demonstrated that doping S and Y in the g-C3N4 lattice increased the separation of the HOMO and LUMO and narrowed the band gap of g-C3N4. This work could provide a facile synthesis of modified CN and promising insights into understanding the mechanism for efficient visible-light photocatalytic performance.

Degradation of Organic Dyes Using the Ionizing Irradiation Process in the Presence of the CN/CD3/Fe6 Composite: Mechanistic Studies

“…These exhibit excellent photocatalytic efficiency during the process of organic pollutant degradation (dye and antibiotic). 13 − 15 g-C 3 N 4 is a low-cost photocatalyst capable of generating H 2 and H 2 O 2 from water, and CDs exhibit high catalytic activity during H 2 O 2 decomposition. Liu et al demonstrated that the combination of g-C 3 N 4 and CDs exhibited a synergism on the processes of H 2 O 2 decomposition and • OH production in the absence of light irradiation.…”

“…To improve the mineralization efficiency of organic pollutants and reduce operating costs, EBI is usually applied with addition of some oxidants like H 2 O 2 , ozone, persulfate, and the metal catalysts such as Fe 2+ and TiO 2 . − Composites formed by graphitic carbon nitride (g-C 3 N 4 )/carbon nanodots (CDs) doped with metals have been extensively studied. These exhibit excellent photocatalytic efficiency during the process of organic pollutant degradation (dye and antibiotic). − g-C 3 N 4 is a low-cost photocatalyst capable of generating H 2 and H 2 O 2 from water, and CDs exhibit high catalytic activity during H 2 O 2 decomposition. Liu et al demonstrated that the combination of g-C 3 N 4 and CDs exhibited a synergism on the processes of H 2 O 2 decomposition and • OH production in the absence of light irradiation .…”

Ultrasonic-assisted synthesis of porous S-doped carbon nitride ribbons for photocatalytic reduction of CO2

“…From the spectra, the atomic contents of the S element were calculated to be 0.75 wt% and 0.86 wt% in SCN and PSCN samples, respectively. The binding energy of S 2p in PSCN at around 168.5 eV was assigned to S—C bonds formed by replacing the N atoms with the S atoms [47] . Furthermore, for SCN and PSCN, similar patterns of C 1 s and N 1 s spectra without significant binding energy shifts were observed.…”

Bandgap Engineering of Melon using Highly Reduced Graphene Oxide for Enhanced Photoelectrochemical Hydrogen Evolution

“…Melon, an uncondensed form of g-C 3 N 4 , attracted attention recently. [27][28][29] It has been used as a precursor for the synthesis of graphitic carbon nitride (g-C 3 N 4 ) since its discovery by Berzelius in the 1830s. [30] It also comprises tri-striazine subunits linked through a planar tertiary amino group with a layered structure.…”

“…In addition, the NH 2 groups on the surface could provide reactive centers for the preparation of composites through covalent tailoring or weak intermolecular interactions with other functional molecules. [34,35] Frequently, attempts are made to overcome the shortcomings of metal-free carbon nitride photocatalysts by substitution (i.e., "doping") with nonmetals, [28,29,36,37] by copolymerization, [38,39] or with hybrid heterostructures or nanocomposites. [40,41] Nanocomposites with conductive materials are an intriguing option to improve the charge separation efficiency of semiconductors.…”