Melem-derived poly(heptazine imide) for effective charge transport and photocatalytic reforming of cellulose into H2 and biochemicals under visible light

Nimbalkar, Dipak B.; Nguyen, Van-Can; Shih, Chun-Yan; Teng, Hsisheng

doi:10.1016/j.apcatb.2022.121601

Cited by 33 publications

(14 citation statements)

References 49 publications

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“…In any event, there is a significant difference in the XRD diffraction patterns in poly(heptazine imide) and poly(triazine imide). All of the poly(heptazine imide) samples show a typical peak located around 8°, − and the poly(triazine imide) shows a representative diffraction peak located around 11°, − which can be clearly observed in the previous research. In this work, the original PHI and RPHI samples exhibit a typical XRD diffraction peak located at 8.06°, indicating the poly(heptazine imide) structure of the samples.…”

Section: Resultssupporting

confidence: 67%

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H₂ Evolution

Wang

Shu

Zhou

et al. 2022

ACS Appl. Mater. Interfaces

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Poly(heptazine imide) (abbreviated as PHI), a heptazine-based crystalline carbon nitride photocatalyst, has attracted widespread attention in the photocatalytic H2 evolution benefiting from its high crystallinity. Nevertheless, the optical absorption range of the directly synthesized PHI is generally narrow, which severely hinders the utilization of visible light. Much research aimed to extend the optical absorption range of PHI; however, either the optimization degree was insufficient or the synthesis process was cumbersome. Herein, red PHI (RPHI) for improving the photocatalytic H2 evolution was facilely synthesized by the one step method. The optimal RPHI sample possesses an obvious new absorption band of the n → π* electron transition and exhibits a significantly enhanced photocatalytic H2 evolution rate of 169 μmol h–1 (λ > 510 nm) and 46 μmol h–1 (λ > 600 nm), which is about 5 times (λ > 510 nm) and 7.7 times (λ > 600 nm) that of pristine PHI and surpasses most reported RPHIs. This work may promote the development of the PHI photocatalyst for near-infrared photocatalytic H2 production.

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Section: Resultssupporting

confidence: 67%

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H₂ Evolution

Wang

Shu

Zhou

et al. 2022

ACS Appl. Mater. Interfaces

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“…30 In contrast, compared to NCN, there is a discernible absorption peak within the 2180−2200 cm −1 region, indicative of the stretching vibration of the cyano unit C�N. 31,32 These findings suggest that NaOH serves as a structure-guiding agent, wherein Na + ions etch and disrupt the conjugated structure of CN during heating, leading to partial decomposition of the heptazine ring structure and thus forming C�N functionalities. This process results in the formation of graphitic-phase carbon nitride with a surface rich in hydroxyl groups, alkalized, and featuring cyano modifications.…”

Section: ■ Experimental Sectionmentioning

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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Section: Introductionmentioning

confidence: 99%

“…More interestingly, the polymer can intercalate free ions from molten salts, which will strengthen the frameworks of polymer crystals . Despite that PHI is highly attractive in the field of photocatalysis because of its unique structure, tunable optical property, and high charge transport nature, its fast photogenerated electron–hole recombination rate restricts its photocatalytic performance …”

Section: Introductionmentioning

confidence: 99%

“…32 Despite that PHI is highly attractive in the field of photocatalysis because of its unique structure, tunable optical property, and high charge transport nature, its fast photogenerated electron−hole recombination rate restricts its photocatalytic performance. 33 In recent years, 2D MXene, as a precursor of in-situ formed TiO 2 , is used to form heterojunction composites with other photoactive materials to improve the overall photocatalytic performance. 34−40 Studies have shown that Ti 3 C 2 nanosheets are unstable and can be transformed into semiconductor TiO 2 in an oxidizing atmosphere.…”

Section: Introductionmentioning

confidence: 99%

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Potassium Poly(heptazine imide) Coupled with Ti₃C₂ MXene-Derived TiO₂ as a Composite Photocatalyst for Efficient Pollutant Degradation

Chen

et al. 2023

ACS Omega

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The photocatalytic degradation of pollutants is an effective and sustainable way to solve environmental problems, and the key is to develop an efficient, low-cost, and stable photocatalyst. Polymeric potassium poly(heptazine imide) (K-PHI), as a new member of the carbon nitride family, is a promising candidate but is characterized by a high charge recombination rate. To solve this problem, K-PHI was in-situ composited with MXene Ti 3 C 2 -derived TiO 2 to construct a type-II heterojunction. The morphology and structure of composite K-PHI/TiO 2 photocatalysts were characterized via different technologies, including TEM, XRD, FT-IR, XPS, and UV–vis reflectance spectra. Robust heterostructures and tight interactions between the two components of the composite were verified. Furthermore, the K-PHI/TiO 2 photocatalyst showed excellent activity for Rhodamine 6G removal under visible light illumination. When the weight percent of K-PHI in the original mixture of K-PHI and Ti 3 C 2 was set to 10%, the prepared K-PHI/TiO 2 composite photocatalyst shows the highest photocatalytic degradation efficiency as high as 96.3%. The electron paramagnetic resonance characterization indicated that the · OH radical is the active species accounting for the degradation of Rhodamine 6G.

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Melem-derived poly(heptazine imide) for effective charge transport and photocatalytic reforming of cellulose into H2 and biochemicals under visible light

Cited by 33 publications

References 49 publications

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H₂ Evolution

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H₂ Evolution

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

Potassium Poly(heptazine imide) Coupled with Ti₃C₂ MXene-Derived TiO₂ as a Composite Photocatalyst for Efficient Pollutant Degradation

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Melem-derived poly(heptazine imide) for effective charge transport and photocatalytic reforming of cellulose into H2 and biochemicals under visible light

Cited by 33 publications

References 49 publications

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H2 Evolution

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H2 Evolution

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

Potassium Poly(heptazine imide) Coupled with Ti3C2 MXene-Derived TiO2 as a Composite Photocatalyst for Efficient Pollutant Degradation

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Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H₂ Evolution

Optimizing the Optical Absorption of Poly(heptazine imide) by the n → π* Electron Transition for Improved Photocatalytic H₂ Evolution

Potassium Poly(heptazine imide) Coupled with Ti₃C₂ MXene-Derived TiO₂ as a Composite Photocatalyst for Efficient Pollutant Degradation