Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H<sub>2</sub>O<sub>2</sub> evolution

Zhang, Xu; Ma, Peijie; Wang, Wenwen; Gan, Li‐Yong; Chen, Xianjie; Zhang, Peng; Wang, Yang; Li, Hui; Wang, Lihua; Zhou, Xiaoyuan; Zheng, Kun

doi:10.1039/d1ee02369a

Cited by 522 publications

(293 citation statements)

References 60 publications

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“…As shown in Figure 1c, there are three component peaks at 287.7, 285.6, and 284.4 eV for PCN, corresponding to NCN bond, CNHx group and adsorbed hydrocarbons, respectively. [ 20 ] Obviously, CNHx peak of KCN and O/KCN samples increases gradually in comparison with PCN, which is consistent with the conclusion that the CN is introduced in the framework since CN shows similar C1s bind energy to CNHx. It can be seen from Figure 1d that the N 1s spectrum of PCN can be fitted into three peaks at 398.2, 399.53, and 400.7 eV, corresponding to bi‐coordinated N (CNC), tri‐coordinated N (N‐3C), and NHx groups in the heptazine framework, respectively.…”

Section: Resultssupporting

confidence: 83%

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H₂O₂ Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Liu

Wang

Chen

et al. 2022

Adv Funct Materials

141

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Photocatalytic hydrogen peroxide (H 2 O 2 ) production from dioxygen and water is regarded as a promising technology since it can achieve sustainable and green solar-to-chemical energy conversion. Herein, oxygen and potassium dual-heteroatom incorporated polymeric carbon nitride (O/KCN) is rationally designed for H 2 O 2 generation with an ultrahigh rate of 309.44 µM h −1 mg −1 , which surpasses that of other C 3 N 4 -based photocatalysts. The enhanced performance can be ascribed to the effective light absorption, fast charge transfer/separation, strong oxygen adsorption, and highly selective twoelectron oxygen reduction reaction (ORR). Density functional theory calculations further confirm that the obtained O/KCN is more favorable than others for electrons migrating from β spin-orbital to π* orbitals of O 2 molecule, thus optimizing O 2 molecule activation to promote the formation of intermediate species *OOH and decrease the energy barrier of H 2 O 2 production. This work not only provides in-depth insights for the photocatalytic H 2 O 2 generation mechanism, but also lays the foundation for further development of highly active photocatalysts for environmental remediation and energy conversion.

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Section: Resultssupporting

confidence: 83%

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H₂O₂ Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Liu

Wang

Chen

et al. 2022

Adv Funct Materials

141

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“…Furthermore, the Ag@CNNS was also evaluated under a dark condition and nitrogen atmosphere, respectively. No H 2 O 2 could be detected, suggesting the importance of visible light and O 2 in the photoredox progress [ 40 ]. Finally, we summarized the performance comparison of g-C 3 N 4 -based photocatalysts for H 2 O 2 production in recent years ( Figure 4 d and Table 1 ).…”

Section: Resultsmentioning

confidence: 99%

“…PCN was synthesized using a conventional thermal polymerization method [ 40 ]. 15 g of urea was placed in a 100 mL alumina crucible with a lid and calcined at 550 °C with a ramping rate of 5 °C/min in a muffle furnace.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of Silver Nanoparticles-Modified Graphitic Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution

et al. 2022

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As a promising metal-free photocatalyst, graphitic carbon nitride (g-C3N4) is still limited by insufficient visible light absorption and rapid recombination of photogenerated carriers, resulting in low photocatalytic activity. Here, we adjusted the microstructure of the pristine bulk-g-C3N4 (PCN) and further loaded silver (Ag) nanoparticles. Abundant Ag nanoparticles were grown on the thin-layer g-C3N4 nanosheets (CNNS), and the Ag nanoparticles decorated g-C3N4 nanosheets (Ag@CNNS) were successfully synthesized. The thin-layer nanosheet-like structure was not only beneficial for the loading of Ag nanoparticles but also for the adsorption and activation of reactants via exposing more active sites. Moreover, the surface plasmon resonance (SPR) effect induced by Ag nanoparticles enhanced the absorption of visible light by narrowing the band gap of the substrate. Meanwhile, the composite band structure effectively promoted the separation and transfer of carriers. Benefiting from these merits, the Ag@CNNS reached a superior hydrogen peroxide (H2O2) yield of 120.53 μmol/g/h under visible light irradiation in pure water (about 8.0 times higher than that of PCN), significantly surpassing most previous reports. The design method of manipulating the microstructure of the catalyst combined with the modification of metal nanoparticles provides a new idea for the rational development and application of efficient photocatalysts.

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“…In the former, adjusting the molecular structure of g-C 3 N 4 to expand its light response and reduce photoinduced charge recombination is an effective method to improve the photocatalytic performance of g-C 3 N 4 . Given the organic properties of the g-C 3 N 4 conjugated structure, g-C 3 N 4 photocatalysts can be very feasibly prepared by adjusting the molecular composition through copolymerization [7,8]. Noticeably, the diversity of organic reactions provides various methods to design supramolecules for modifying g-C 3 N 4 with nitrogen-rich precursors and comonomers.…”

Section: Introductionmentioning

confidence: 99%

H2+CO2 Synergistic Plasma Positioning Carboxyl Defects in g-C3N4 with Engineered Electronic Structure and Active Sites for Efficient Photocatalytic H2 Evolution

Wang

Zhang

et al. 2022

IJMS

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Defective functional-group-endowed polymer semiconductors, which have unique photoelectric properties and rapid carrier separation properties, are an emerging type of high-performance photocatalyst for various energy and environmental applications. However, traditional oxidation etching chemical methods struggle to introduce defects or produce special functional group structures gently and controllably, which limits the implementation and application of the defective functional group modification strategy. Here, with the surface carboxyl modification of graphitic carbon nitride (g-C3N4) photocatalyst as an example, we show for the first time the feasibility and precise modification potential of the non-thermal plasma method. In this method, the microwave plasma technique is employed to generate highly active plasma in a combined H2+CO2 gas environment. The plasma treatment allows for scalable production of high-quality defective carboxyl group-endowed g-C3N4 nanosheets with mesopores. The rapid H2+CO2 plasma immersion treatment can precisely tune the electronic and band structures of g-C3N4 nanosheets within 10 min. This conjoint approach also promotes charge-carrier separation and accelerates the photocatalyst-catalyzed H2 evolution rate from 1.68 mmol h−1g−1 (raw g-C3N4) to 8.53 mmol h−1g−1 (H2+CO2-pCN) under Xenon lamp irradiation. The apparent quantum yield (AQY) of the H2+CO2-pCN with the presence of 5 wt.% Pt cocatalyst is 4.14% at 450 nm. Combined with density functional theory calculations, we illustrate that the synergistic N vacancy generation and carboxyl species grafting modifies raw g-C3N4 materials by introducing ideal defective carboxyl groups into the framework of heptazine ring g-C3N4, leading to significantly optimized electronic structure and active sites for efficient photocatalytic H2 evolution. The 5.08-times enhancement in the photocatalytic H2 evolution over the as-developed catalysts reveal the potential and maneuverability of the non-thermal plasma method in positioning carboxyl defects and mesoporous morphology. This work presents new understanding about the defect engineering mechanism in g-C3N4 semiconductors, and thus paves the way for rational design of effective polymeric photocatalysts through advanced defective functional group engineering techniques evolving CO2 as the industrial carrier gas.

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Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H₂O₂ evolution

Abstract: Defect engineering modified graphite carbon nitride (g-C3N4) has been widely used in various photocatalytic systems due to the enhanced catalytic activity by multiple defect sites (such as vacancies or functional...

Cited by 522 publications

References 60 publications

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H₂O₂ Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H₂O₂ Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Synthesis of Silver Nanoparticles-Modified Graphitic Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution

H2+CO2 Synergistic Plasma Positioning Carboxyl Defects in g-C3N4 with Engineered Electronic Structure and Active Sites for Efficient Photocatalytic H2 Evolution

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Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H2O2 evolution

Abstract: Defect engineering modified graphite carbon nitride (g-C3N4) has been widely used in various photocatalytic systems due to the enhanced catalytic activity by multiple defect sites (such as vacancies or functional...

Cited by 522 publications

References 60 publications

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H2O2 Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H2O2 Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Synthesis of Silver Nanoparticles-Modified Graphitic Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution

H2+CO2 Synergistic Plasma Positioning Carboxyl Defects in g-C3N4 with Engineered Electronic Structure and Active Sites for Efficient Photocatalytic H2 Evolution

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Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H₂O₂ evolution

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H₂O₂ Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H₂O₂ Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride