Tailoring phenol photomineralization pathway over polymeric carbon nitride with cyano group multifunctional active sites

Polymeric carbon nitride is a promising candidate for metal-free photocatalysis, but it is hampered by low activity due to poor carrier separation efficiency and lack of active sites.

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Mechanistic analysis of multiple processes controlling solar-driven H2O2 synthesis using engineered polymeric carbon nitride

Nature Communications ◽

10.1038/s41467-021-24048-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yubao Zhao ◽

Peng Zhang ◽

Zhenchun Yang ◽

Lina Li ◽

Jingyu Gao ◽

...

Keyword(s):

Active Sites ◽

Carbon Nitride ◽

Separation Efficiency ◽

Structural Features ◽

Reduction Reaction ◽

Transformation Process ◽

Photon Absorption ◽

Apparent Quantum Yield ◽

Dioxygen Reduction ◽

Polymeric Carbon

AbstractSolar-driven hydrogen peroxide (H2O2) production presents unique merits of sustainability and environmental friendliness. Herein, efficient solar-driven H2O2 production through dioxygen reduction is achieved by employing polymeric carbon nitride framework with sodium cyanaminate moiety, affording a H2O2 production rate of 18.7 μmol h −1 mg−1 and an apparent quantum yield of 27.6% at 380 nm. The overall photocatalytic transformation process is systematically analyzed, and some previously unknown structural features and interactions are substantiated via experimental and theoretical methods. The structural features of cyanamino group and pyridinic nitrogen-coordinated soidum in the framework promote photon absorption, alter the energy landscape of the framework and improve charge separation efficiency, enhance surface adsorption of dioxygen, and create selective 2e− oxygen reduction reaction surface-active sites. Particularly, an electronic coupling interaction between O2 and surface, which boosts the population and prolongs the lifetime of the active shallow-trapped electrons, is experimentally substantiated.

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Water-Soluble Polymeric Carbon Nitride Colloidal Nanoparticles for Highly Selective Quasi-Homogeneous Photocatalysis

10.26434/chemrxiv.9879947.v1 ◽

2019 ◽

Author(s):

Igor Krivtsov ◽

Dariusz Mitoraj ◽

Marina Ilkaeva ◽

Mariana Sardo ◽

Luís Mafra ◽

...

Keyword(s):

Active Sites ◽

Carbon Nitride ◽

Water Soluble ◽

Colloidal Nanoparticles ◽

Narrow Size Distribution ◽

New Paradigm ◽

Redox Transformations ◽

Homogeneous Photocatalysis ◽

Polymeric Carbon ◽

First Time

Heptazine-based polymeric carbon nitrides (PCN) are well established as promising photocatalysts for light-driven redox transformations. However, the activity of these materials is hampered by their low surface area translating into low concentration of active sites accessible for reactants. Herein, we report, for the first time, a bottom-up preparation of PCN nanoparticles with a narrow size distribution (~10±3 nm), which are fully soluble in water showing no gelation or precipitation over several months, and allow carrying out photocatalysis under quasi-homogeneous conditions. The rate of selective (up to 100%) photooxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde was enhanced by the factor of 6.5 as compared to conventional solid PCN and was accompanied by simultaneous H2O2 production via reduction of oxygen. The dissolved photocatalyst can be easily recovered and re-dissolved by simple modulation of the ionic strength of the medium, without any loss of activity and selectivity. This work thus establishes a new paradigm of easily operable quasi-homogeneous photocatalysis with PCN, and opens up a route for other applications in which liquid aqueous operation or processing of PCN is required.

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Water-Soluble Polymeric Carbon Nitride Colloidal Nanoparticles for Highly Selective Quasi-Homogeneous Photocatalysis

10.26434/chemrxiv.9879947 ◽

2019 ◽

Author(s):

Igor Krivtsov ◽

Dariusz Mitoraj ◽

Marina Ilkaeva ◽

Mariana Sardo ◽

Luís Mafra ◽

...

Keyword(s):

Active Sites ◽

Carbon Nitride ◽

Water Soluble ◽

Colloidal Nanoparticles ◽

Narrow Size Distribution ◽

New Paradigm ◽

Redox Transformations ◽

Homogeneous Photocatalysis ◽

Polymeric Carbon ◽

First Time

Heptazine-based polymeric carbon nitrides (PCN) are well established as promising photocatalysts for light-driven redox transformations. However, the activity of these materials is hampered by their low surface area translating into low concentration of active sites accessible for reactants. Herein, we report, for the first time, a bottom-up preparation of PCN nanoparticles with a narrow size distribution (~10±3 nm), which are fully soluble in water showing no gelation or precipitation over several months, and allow carrying out photocatalysis under quasi-homogeneous conditions. The rate of selective (up to 100%) photooxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde was enhanced by the factor of 6.5 as compared to conventional solid PCN and was accompanied by simultaneous H2O2 production via reduction of oxygen. The dissolved photocatalyst can be easily recovered and re-dissolved by simple modulation of the ionic strength of the medium, without any loss of activity and selectivity. This work thus establishes a new paradigm of easily operable quasi-homogeneous photocatalysis with PCN, and opens up a route for other applications in which liquid aqueous operation or processing of PCN is required.

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One-step preparation of novel K+ and cyano-group co-doped crystalline polymeric carbon nitride with highly efficient H2 evolution

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2020.125023 ◽

2020 ◽

Vol 601 ◽

pp. 125023 ◽

Cited By ~ 3

Author(s):

Ping Deng ◽

Lei Shi ◽

Haihua Wang ◽

Wei Qi

Keyword(s):

Carbon Nitride ◽

Cyano Group ◽

H2 Evolution ◽

Highly Efficient ◽

One Step ◽

Polymeric Carbon ◽

Co Doped

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Etching-induced highly porous polymeric carbon nitride with enhanced photocatalytic hydrogen evolution

Chemical Communications ◽

10.1039/d1cc00214g ◽

2021 ◽

Author(s):

Xiang Wang ◽

Yuguo Xia ◽

Haimei Wang ◽

Xiuling Jiao ◽

Dairong Chen

Keyword(s):

Specific Surface ◽

Surface Charge ◽

Surface Area ◽

Charge Separation ◽

Active Sites ◽

Carbon Nitride ◽

Separation Process ◽

Large Specific Surface Area ◽

Polymeric Carbon ◽

Highly Porous

Photocatalytic catalysts with a large specific surface area generally can not only supply more active sites but also facilitate the surface charge separation process. Here, we present a facile strategy...

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Atomic-Level Localization of π-Electrons in Defect Engineered Tri-s-triazine Units for Increased Photocatalytic Hydrogen Generation of Polymeric Carbon Nitride

Catalysis Science & Technology ◽

10.1039/d1cy00938a ◽

2021 ◽

Author(s):

Mengqi Xue ◽

Dao Chuan Jiang ◽

Haiwei Du ◽

Zhongjun Li ◽

Hong Bi ◽

...

Keyword(s):

Active Sites ◽

Carbon Nitride ◽

Hydrogen Generation ◽

Atomic Level ◽

Charge Carriers ◽

H2 Generation ◽

Photocatalytic Hydrogen Generation ◽

Catalytically Active ◽

Photocatalytic H2 Generation ◽

Polymeric Carbon

Localizing charge carriers close to catalytically active sites can reduce the charge recombination in photoexcited polymeric carbon nitride (PCN), which thus potentially increases its photocatalytic H2 generation. However, this strategy...

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Dissolution and Performing Homogeneous Photocatalysis of Polymeric Carbon Nitride

10.26434/chemrxiv.6959627 ◽

2018 ◽

Author(s):

Chaofeng Huang ◽

Jing Wen ◽

Yanfei Shen ◽

Fei He ◽

Li Mi ◽

...

Keyword(s):

Conjugated Polymer ◽

Carbon Nitride ◽

Heterogeneous Catalysts ◽

Methane Sulfonic Acid ◽

Environment Friendly ◽

The Poor ◽

Catalytic Sites ◽

Homogeneous Photocatalysis ◽

Polymeric Carbon ◽

First Time

<a></a><a>As a metal-free conjugated polymer, carbon nitride (CN) has attracted tremendous attention as heterogeneous (photo)catalysts. </a><a></a><a>By following prototype of enzymes, making all catalytic sites of accessible via homogeneous reactions is a promising approach toward maximizing CN activity, but hindered due to </a><a></a><a>the poor insolubility of CN</a>. Herein, we report the dissolution of CN in environment-friendly methane sulfonic acid and the homogeneous photocatalysis driven by CN for the first time with the activity boosted up to 10-times, comparing to the heterogeneous counterparts. Moreover, facile recycling and reusability, the <a>hallmark</a> of heterogeneous catalysts, were kept for the homogeneous CN photocatalyst via reversible precipitation using poor solvents. It opens new vista of CN in homogeneous catalysis and offers a successful example of polymeric catalysts in bridging gaps of homo/heterogeneous catalysis.

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