NH-rich red poly(heptazine imide) nanoparticles with simultaneously promoted exciton dissociation and activated n → π* electronic transition for boosted photocatalytic H<sub>2</sub> generation

Zhao, Zhengliang; Shu, Zhu; Zhou, Jun; Ye, Lina; Li, Tiantian; Wang, Wenbin; Xu, Lina

doi:10.1039/d2ta04213d

Cited by 7 publications

(5 citation statements)

References 57 publications

(101 reference statements)

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“…From Figure 4b, it can be detected that the E g of Vs‐ZIS was determined to 2.18 eV by extending the liner part of K – M plot to × axis. [ 45 ] Likewise, the E g of Vs‐ZIS/SnSe 2 and SnSe 2 were intended to be 1.92 and 0.95 eV, respectively. The narrower E g of Vs‐ZIS/SnSe 2 than that of Vs‐ZIS indicates the stronger photocarriers generation ability of Vs‐ZIS/SnSe 2 .…”

Section: Resultsmentioning

confidence: 99%

Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

et al. 2022

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The development of a noble‐metal‐free cocatalyst is of great significance for boosting photocatalytic H2 evolution performance. Herein, SnSe2 is developed as a cocatalyst to in situ attachment on the surface of sulfur defect rich ZnIn2S4 (Vs‐ZIS) via a simple hydrothermal method. Owing to the intimate atomic‐level interface and the different work function between Vs‐ZIS and SnSe2, a particular Ohmic junction with internal electric field is formed in Vs‐ZIS/SnSe2, which facilitates the electrons in Vs‐ZIS transfer to SnSe2 and participate in H2 evolution reaction rapidly. Moreover, the abundant S vacancies also benefit the separation of photocarriers in Vs‐ZIS/SnSe2. The optimized Vs‐ZIS/SnSe2 photocatalyst performs a high H2 evolution rate of 29.34 mmol h−1 g−1 under visible light (λ > 420 nm) and an apparent quantum efficiency of 12.25% at 420 nm. Herein, constructive model on developing effective cocatalyst is afforded, and expediting photocarriers transfer through interfacial modulating.

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Section: Resultsmentioning

confidence: 99%

Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

et al. 2022

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“…Currently, molten salts, such as NaCl and KCl, with well-defined melting points, are recognized as key agents for promoting high crystallinity in CN, particularly in the form of poly(heptazine imide) (PHI). 19 However, the synthesis of PHI assisted by NaCl and KCl typically demands elevated temperatures, usually ≥500 °C. Consequently, the strategy of low-temperature PHI synthesis remains underexplored, presenting a significant challenge yet holding crucial practical application value.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Addressing this challenge necessitates an increase in the CN crystallinity. Currently, molten salts, such as NaCl and KCl, with well-defined melting points, are recognized as key agents for promoting high crystallinity in CN, particularly in the form of poly(heptazine imide) (PHI) . However, the synthesis of PHI assisted by NaCl and KCl typically demands elevated temperatures, usually ≥500 °C.…”

Section: Introductionmentioning

confidence: 99%

Low-Temperature Synthesis of Cyano-Rich Modified Surface-Alkalinized Heterojunctions with Directional Charge Transfer for Photocatalytic In Situ Generation and Consumption of Peroxides

Zhu,

Zhao,

Duan

et al. 2024

ACS Appl. Mater. Interfaces

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The synthesis of low-temperature poly(heptazine imide) (PHI) presents a significant challenge. In this context, we have developed a novel lowtemperature synthesis strategy for PHI in this work. This strategy involves the introduction of Na + ions, which etch and disrupt the conjugated structure of carbon nitride (CN) during assisted thermal condensation. This disruption leads to the partial decomposition of the heptazine ring structure, resulting in the formation of C�N functionalities on the CN surface, which are enriched with hydroxyl groups and undergo cyano modification. The formation of heterojunctions between CN and ZnO, which facilitate charge transfer along an immobilization pathway, accelerated charge transfer processes and improved reactant adsorption as well as electron utilization efficiency. The resulting catalyst was employed for the room temperature, atmospheric pressure, and solvent-free photocatalytic selective oxidation of cumene (CM), achieving a cumene conversion rate of 28.7% and a remarkable selectivity of 92.0% toward the desired product, cumene hydroperoxide (CHP). Furthermore, this CHP induced oxidative reactions, as demonstrated by the successful oxidation of benzylamine to imine and the oxidation of sulfide to sulfoxide, both yielding high product yields. Additionally, the utilization of a continuous-flow device significantly reduces the reaction time required for these oxidation processes. This work not only introduces an innovative approach to environmentally friendly, sustainable, clean, and efficient PHI synthesis but also underscores the promising potential and advantages of carbon nitride-based photocatalysts in the realm of sustainable and green organic transformations.

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“…As melon with a building unit of heptazine, poly(heptazine imide) (PHI) is a real 2D carbon nitride configured by in-plane imide-bridged covalent bonds. − Metal-intercalated PHIs have been produced from the nitrogen-abundant organic solid precursors or melon-based carbon nitrides by the ionothermal method in suitable salt melts. Metal-free PHI is attainable as the metal-intercalated PHI is treated in acid solution to have proton-exchanged PHI (HPHI) .…”

Section: Introductionmentioning

confidence: 99%

“…The heptazine-based crystalline 2D carbon nitride with a well-conjugated PHI network has a rather swift charge transport rate that is beneficial to reduce the recombination of photogenerated electron–hole pairs . Accordingly, the photocatalytic activity of the optimized PHI for H 2 evolution is superior to the melon-based carbon nitride. − …”

Section: Introductionmentioning

confidence: 99%

Carbon Vacancy-Modified Carbon Nitride Allotropic Composite for Solar Hydrogen Generation Coupled with Selective Oxidation of 5-Hydroxymethylfurfural

Chen

Tsai

Liu

et al. 2023

ACS Sustainable Chem. Eng.

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A melon-poly(heptazine imide) (PHI) carbon nitride allotropic composite is constructed by partial phase conversion of melon-based carbon nitride through hydrothermal treatment using pure water. Solid-state nuclear magnetic resonance characterization reveals the existence of the intrinsic defects of carbon vacancies in the melon-PHI carbon nitride allotropic composite. In the presence of the Pt nanoparticle cocatalyst and the hole scavenger of triethanolamine, the carbon vacancy-modified melon-PHI allotropic composite exhibits superior photocatalytic performance for hydrogen production compared to the pristine melon-based carbon nitride. Moreover, the simultaneous H2 evolution from water splitting coupled with selective oxidation of 5-(hydroxymethyl) furfural to 2,5-diformylfuran is achieved over the carbon vacancy-modified melon-PHI allotropic composite photocatalyst with activities of 41 and 49 μmol g–1 h–1 under AM 1.5G (100 mW cm–2) illumination with a UV filter. Density functional theory calculations suggest that the defective heptazine rings with carbon vacancies locate in the PHI portion and contribute to the major charge density of the highest occupied molecular orbital in the PHI portion of the the allotropic composite. This intrinsic defect allows the improvement of photocharge separation and the creation of additional active sites in the carbon nitride photocatalyst to boost the performances of photocatalytic redox reactions.

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NH-rich red poly(heptazine imide) nanoparticles with simultaneously promoted exciton dissociation and activated n → π* electronic transition for boosted photocatalytic H₂ generation

Abstract: The efficiencies of visible-light utilization and exciton dissociation are crucial for photocatalytic H2 evolution of poly(heptazine imide) (PHI), but simultaneously achieving both goals is still a grave challenge. Herein, we...

Cited by 7 publications

References 57 publications

Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

Low-Temperature Synthesis of Cyano-Rich Modified Surface-Alkalinized Heterojunctions with Directional Charge Transfer for Photocatalytic In Situ Generation and Consumption of Peroxides

Carbon Vacancy-Modified Carbon Nitride Allotropic Composite for Solar Hydrogen Generation Coupled with Selective Oxidation of 5-Hydroxymethylfurfural

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NH-rich red poly(heptazine imide) nanoparticles with simultaneously promoted exciton dissociation and activated n → π* electronic transition for boosted photocatalytic H2 generation

Abstract: The efficiencies of visible-light utilization and exciton dissociation are crucial for photocatalytic H2 evolution of poly(heptazine imide) (PHI), but simultaneously achieving both goals is still a grave challenge. Herein, we...

Cited by 7 publications

References 57 publications

Fabrication of Sulfur Defect Rich ZnIn2S4/SnSe2 Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

Fabrication of Sulfur Defect Rich ZnIn2S4/SnSe2 Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

Low-Temperature Synthesis of Cyano-Rich Modified Surface-Alkalinized Heterojunctions with Directional Charge Transfer for Photocatalytic In Situ Generation and Consumption of Peroxides

Carbon Vacancy-Modified Carbon Nitride Allotropic Composite for Solar Hydrogen Generation Coupled with Selective Oxidation of 5-Hydroxymethylfurfural

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NH-rich red poly(heptazine imide) nanoparticles with simultaneously promoted exciton dissociation and activated n → π* electronic transition for boosted photocatalytic H₂ generation

Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion