Preparation of double-vacancy modified carbon nitride to greatly improve the activity of photocatalytic hydrogen generation

Lin, Yinjun; Yang, Yuanyuan; Guo, Wenting; Wang, Lifen; Zhang, Ruiqin; Liu, Yonggang; Zhai, Yunpu

doi:10.1016/j.apsusc.2021.150029

Cited by 23 publications

(6 citation statements)

References 55 publications

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“…The chemical structures of CN and CN-X were analyzed via FTIR. As displayed in Figure a, the band for 810 cm –1 corresponding to the characteristic breathing vibration of tri- s -triazine units ring was consistent with previous studies, − and the region of 1200–1600 cm –1 corresponded to C–N heterocycles . It was indicated that the CN- X displayed a similar FTIR spectrum compared with CN, which proved that the steam activation did not destroy the main structure of CN- X .…”

Section: Resultssupporting

confidence: 87%

Vacancy-Modified Porous g-C₃N₄ Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

et al. 2023

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As a promising photocatalyst material, g-C 3 N 4 has great application potential in energy production and environmental improvement. In this work, surface-modified g-C 3 N 4 nanosheets with excellent stability and high photocatalytic activity were successfully synthesized by physical steam activation. The charge transfer rate of carbon nitride was improved due to the synergistic effect of nitrogen defect and oxygen doping caused by steam activation. Meanwhile, the specific surface area and pore volume of the optimized sample reached 124.3 m 2 g −1 and 0.42 cm 3 g −1 , respectively, which increased the exposed reaction sites of reactants, enhancing the photocatalytic activity of g-C 3 N 4 . In addition, this novel g-C 3 N 4 displayed a great H 2 evolution rate of 5889.39 μmol h −1 g −1 with a methylene blue degradation rate up to 6.52 × 10 −3 min −1 , which was 3.7 and 2.1 times of original g-C 3 N 4 , respectively. This study provided a simple and economical method to develop a highly efficient g-C 3 N 4 photocatalyst for solar energy conversion.

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Section: Resultssupporting

confidence: 87%

Vacancy-Modified Porous g-C₃N₄ Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

et al. 2023

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“…Because the surface OVs are good electron-capturing traps, the higher the content of surface OVs, the more the electrons will be captured by these surface OVs. In other words, more photoexcited electrons in the CB are moved to intermediate band gap states instead of recombining with photogenerated holes and thus promote the separation of electron–hole pairs . Accordingly, the lifetime of carriers is prolonged.…”

Section: Resultsmentioning

confidence: 99%

“…In other words, more photoexcited electrons in the CB are moved to intermediate band gap states instead of recombining with photogenerated holes and thus promote the separation of electron−hole pairs. 49 Accordingly, the lifetime of carriers is prolonged.…”

Section: Crystal Phase and Morphologymentioning

confidence: 99%

Improving the Surface Oxygen Vacancy Concentration of Bi₂O₄ through the Pretreatment of the NaBiO₃·2H₂O Precursor as a High-Performance Visible Light Photocatalyst

et al. 2022

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The oxygen-deficient bismuth oxide, Bi 2 O 4 , synthesized by a typical hydrothermal method using commercial NaBiO 3 • 2H 2 O as a raw material only has a relatively low concentration of surface oxygen vacancies (OVs). How to improve the visible light photocatalytic performance of Bi 2 O 4 via tuning its surface OV concentration is still a huge challenge. In this study, improving the surface OVs of Bi 2 O 4 was successfully realized through the pretreatment of commercial NaBiO 3 •2H 2 O, including thermal treatment in air and hydrothermal treatment in 10 M NaOH solution, forming NaBiO 3 •xH 2 O intermediate products first, and then hydrothermal preparation of Bi 2 O 4 target products using NaBiO 3 •xH 2 O instead of commercial NaBiO 3 •2H 2 O as the precursor. The enhanced surface OV content not only narrows the band gap of Bi 2 O 4 and thus extends its optical response range but also captures more photoexcited electrons and thus increases the charge carriers' separation efficiency and prolongs the charge carriers' lifetime of Bi 2 O 4 . Among the above-mentioned two pretreatment methods, the effects of the hydrothermal pretreatment are superior to those of the thermal treatment, involving the increase of surface OVs, the optical harvesting capacity, and the charge carriers' separation efficiency. Accordingly, Bi 2 O 4 prepared by the hydrothermal pretreatment route exhibits the optimal visible light catalytic performance toward the removal of methyl orange (MO) and phenol due to its most abundant surface OV concentration, which is 2.59 times and 4.26 times higher than that of Bi 2 O 4 synthesized directly by the commercial NaBiO 3 •2H 2 O route, respectively. Holes (h + ) and superoxide radicals ( • O 2 − ) are identified as the main active species, while singlet oxygen ( 1 O 2 ) and hydroxyl radicals ( • OH) are verified as the second and third important active species for organic pollutant removal, respectively. This work has developed a novel strategy to promote the catalytic performance of single Bi 2 O 4 induced by the enhanced surface OV concentration through the pretreatment of the precursor, commercial NaBiO 3 • 2H 2 O.

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“…After irradiation for 1 h, the intensity of the ESR signal decreased in the order: blank > CNA/CNU > CCNA/CCNU. As TEMPO can be oxidized to the ESR-silent TEMPO + by photogenerated h + , 58 the weak ESR signal indicates more efficient generation of h + by CCNA/CCNU upon irradiation. Both DMPO and TEMP are ESR inactive (Fig.…”

Section: Resultsmentioning

confidence: 99%

Molten salt synthesis of a highly crystalline graphitic carbon nitride homojunction from a deep eutectic solvent for selective photocatalytic oxidation

Chen

Tan

et al. 2023

J. Mater. Chem. A

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Preparation of double-vacancy modified carbon nitride to greatly improve the activity of photocatalytic hydrogen generation

Cited by 23 publications

References 55 publications

Vacancy-Modified Porous g-C₃N₄ Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

Vacancy-Modified Porous g-C₃N₄ Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

Improving the Surface Oxygen Vacancy Concentration of Bi₂O₄ through the Pretreatment of the NaBiO₃·2H₂O Precursor as a High-Performance Visible Light Photocatalyst

Molten salt synthesis of a highly crystalline graphitic carbon nitride homojunction from a deep eutectic solvent for selective photocatalytic oxidation

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Preparation of double-vacancy modified carbon nitride to greatly improve the activity of photocatalytic hydrogen generation

Cited by 23 publications

References 55 publications

Vacancy-Modified Porous g-C3N4 Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

Vacancy-Modified Porous g-C3N4 Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

Improving the Surface Oxygen Vacancy Concentration of Bi2O4 through the Pretreatment of the NaBiO3·2H2O Precursor as a High-Performance Visible Light Photocatalyst

Molten salt synthesis of a highly crystalline graphitic carbon nitride homojunction from a deep eutectic solvent for selective photocatalytic oxidation

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Vacancy-Modified Porous g-C₃N₄ Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

Vacancy-Modified Porous g-C₃N₄ Nanosheets Controlled by Physical Activation for Highly Efficient Visible-Light-Driven Hydrogen Evolution and Organics Degradation

Improving the Surface Oxygen Vacancy Concentration of Bi₂O₄ through the Pretreatment of the NaBiO₃·2H₂O Precursor as a High-Performance Visible Light Photocatalyst