Crystallization, cyanamide defect and ion induction of carbon nitride: Exciton polarization dissociation, charge transfer and surface electron density for enhanced hydrogen evolution

Yuan, Jili; Tang, Yanhong; Yi, Xuanying; Liu, Chengbin; Li, Can; Zeng, Yunxiong; Luo, Shenglian

doi:10.1016/j.apcatb.2019.03.069

Cited by 97 publications

(60 citation statements)

References 53 publications

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“…The following characterizations were described in refs and : powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman, energy-dispersive spectroscopy (EDS), solid-state nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization (ESI), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), specific surface area (BET), and photoluminescence (PL).…”

Section: Methodsmentioning

confidence: 99%

Efficient Photocatalytic Hydrogen Evolution and CO₂ Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C₃N₄

Yuan

Tang

et al. 2020

ACS Appl. Mater. Interfaces

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Although graphitic carbon nitride (g-C3N4) has been identified as a promising photocatalyst, pristine g-C3N4 has a limited light absorption, insolubility, small specific surface area, and rapid electron–hole pair recombination. In this study, hydroxyl-grafted oxygen-linked tri-s-triazine-based polymer (HGONTP) is achieved through the polycondensation of hydrothermally pretreated dicyandiamide (DCDA). The content of C–O–C linkers and terminal OH groups in HGONTP can be regulated by the cyclization and hydrolysis degrees of DCDA through the replacement of the pendant NH2 groups with OH groups. The HGONTP photocatalyst exhibits an outstanding light absorption from UV to near-IR, possessing a narrow band gap of 2.18 eV, a hydrophilic surface, a large specific surface area of 96.1 m2 g–1, and reduced charge recombination. As a result, HGONTP exhibits a hydrogen evolution rate 27.7-fold higher than that for pristine g-C3N4 (6.54 vs 0.236 mmol g–1 h–1). The apparent quantum yield reaches 12.6% at 420 nm and 4.1% at 500 nm. In addition, the photocatalytic conversion efficiency of CO2 to CO reaches as high as 3.3 μmol g–1 h–1 without cocatalysts and sacrificial agents. The selectivity of CO2 to CO achieves 88.4%. The proposed strategy paves a new avenue to design high-performance polymeric photocatalysts used in water.

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Section: Methodsmentioning

confidence: 99%

Efficient Photocatalytic Hydrogen Evolution and CO₂ Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C₃N₄

Yuan

Tang

et al. 2020

ACS Appl. Mater. Interfaces

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“…It is worth noting that the obvious stretching vibration peaks at 2290 cm −1 are observed in the Fe−CN‐x samples, which prove the existence of C≡N group [29] . The FTIR results indicate that the iron acetylacetonate promotes the opening of heptazine heterocycles during the polymerization of melamine, thus introducing C≡N group into the sample [30,31] …”

Section: Resultsmentioning

confidence: 87%

Synergy of Iron Doping and Cyano Groups for Enhanced Photocatalytic Hydrogen Production over C₃N₄

Xiao

Zhang

et al. 2021

Chemistry A European J

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Improving the insufficient carrier separation dynamics is still of significance in carbon nitride (C3N4) research. Extensive research has been devoted to improving the carrier separation efficiency through a single strategy, while ignoring the synergistic enhancement effect produced by coupling two or more conventional strategies. Herein, we reported the fabrication of cyano group‐containing Fe‐doped C3N4 porous materials via direct co‐calcination of iron acetylacetonate and melamine for synergistically improving the photocatalytic performance. Iron acetylacetonate can promote the generation of cyano groups and form Fe‐doping in C3N4, thereby increasing the visible‐light absorption and reactive sites. Further, the internal donor‐acceptor system formed by cyano groups and Fe‐doped sites promoted charge carrier separation and inhibited the radiation recombination of e−‐h+ pairs. The optimized photocatalytic activity of Fe−CN‐2 sample was 4.5 times of bulk C3N4 (BCN).

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“…[ 150 ] Similarly, by comparing the slopes of the Mott–Schottky plot, the carrier density of different photocatalysts can be evaluated in which a smaller value corresponds to a higher carrier density at the contact interface. [ 37,63 ] Besides, the transient electron distribution and dynamic electron transport can be detailedly recorded by time‐resolved photoemission electron microscopy. [ 161,162 ] Benefited from such technology, imaging the motion of photoexcited electrons from high‐energy to low‐energy states could be achieved in a type‐II 2D InSe/GaAs heterostructure.…”

Section: Qualitative and Quantitative Characterizations For Ief Deter...mentioning

confidence: 99%

Internal Electric Field on Steering Charge Migration: Modulations, Determinations and Energy‐Related Applications

Yue

Fan

Xiang

2021

Adv Funct Materials

110

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Energy‐related problems induced by ever‐continuous fossil consumption have arisen as one of the most challenging issues in the 21st century, imposing urgent demands on advanced materials to achieve high energy utilization and a sustainable society. In various solar energy utilization and solar‐to‐fuel energy conversion processes, charge carriers are the main and inevitable participators, and the charge dynamics related to their generation, migration, separation, and utilization is the key to advance the material design for settling the above issues. Internal electric field (IEF), also named as built‐in electric field, could guide directional migration of charge carriers, achieving effective charge separation, utilization, and prolonged lifetimes. This critical review begins with the discussion on various modulation strategies toward the IEF together with in‐detail elucidated mechanisms on its formation. Some cascade systems for telling the conclusive role from the induced IEF and the intrinsic design strategy are discussed. Then, a summary of the state‐of‐the‐art advances in the characterization means toward the IEF from both quantitative and qualitative perspectives is provided. Finally presented are IEF modulations in several specific energy‐related applications concerning solar cell, photocatalysis, photodetectors, and batteries to better understand its superiority for well‐performed material design, followed by perspectives on future development and opportunities of the IEF design.

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Crystallization, cyanamide defect and ion induction of carbon nitride: Exciton polarization dissociation, charge transfer and surface electron density for enhanced hydrogen evolution

Cited by 97 publications

References 53 publications

Efficient Photocatalytic Hydrogen Evolution and CO₂ Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C₃N₄

Efficient Photocatalytic Hydrogen Evolution and CO₂ Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C₃N₄

Synergy of Iron Doping and Cyano Groups for Enhanced Photocatalytic Hydrogen Production over C₃N₄

Internal Electric Field on Steering Charge Migration: Modulations, Determinations and Energy‐Related Applications

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Crystallization, cyanamide defect and ion induction of carbon nitride: Exciton polarization dissociation, charge transfer and surface electron density for enhanced hydrogen evolution

Cited by 97 publications

References 53 publications

Efficient Photocatalytic Hydrogen Evolution and CO2 Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C3N4

Efficient Photocatalytic Hydrogen Evolution and CO2 Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C3N4

Synergy of Iron Doping and Cyano Groups for Enhanced Photocatalytic Hydrogen Production over C3N4

Internal Electric Field on Steering Charge Migration: Modulations, Determinations and Energy‐Related Applications

Contact Info

Product

Resources

About

Efficient Photocatalytic Hydrogen Evolution and CO₂ Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C₃N₄

Efficient Photocatalytic Hydrogen Evolution and CO₂ Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C₃N₄

Synergy of Iron Doping and Cyano Groups for Enhanced Photocatalytic Hydrogen Production over C₃N₄