Identification and Analysis of Multiple Factors Controlling Solar-driven H2O2 Synthesis Using Engineered Polymeric Carbon Nitride

Abstract Solar-driven hydrogen peroxide (H2O2) production presents unique merits of sustainability and environmental friendliness. Herein, highly efficient solar-driven H2O2 production through dioxygen reduction is achieved by employing polymeric carbon nitride (PCN) framework with sodium cyanaminate moiety (PCN-NaCA), affording a superior H2O2 production rate of 175 μmol/h on 10 mg photocatalyst and a notable apparent quantum yield of 27.6% at 380 nm. The overall photocatalytic transformation process is systematically analyzed using various steady-state/transient spectroscopic and computational methods. The presence of sodium cyanaminate moiety in PCN-NaCA induces the following multiple effects: enhancing photon absorption, creating the coexistence of p-type and n-type domains, strengthening surface adsorption of dioxygen, and favoring highly selective 2e− ORR. In particular, the adsorption of dioxygen on PCN-NaCA enhances the population and lifetime of trapped electrons in the ps-ns time regime, which should have a notable synergic effect on oxygen reduction process.

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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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Bifunctional hydroxyl group over polymeric carbon nitride to achieve photocatalytic H2O2 production in ethanol aqueous solution with an apparent quantum yield of 52.8% at 420 nm

Chemical Communications ◽

10.1039/c9cc07342f ◽

2019 ◽

Vol 55 (88) ◽

pp. 13279-13282 ◽

Cited By ~ 5

Author(s):

Weishu Hou ◽

Yunxiang Li ◽

Shuxin Ouyang ◽

Huayu Chen ◽

Jinhua Ye ◽

...

Keyword(s):

Aqueous Solution ◽

Quantum Yield ◽

Carbon Nitride ◽

Hydroxyl Group ◽

H2o2 Production ◽

Apparent Quantum Yield ◽

Ethanol Aqueous Solution ◽

Polymeric Carbon

Hydroxyl group modified polymeric carbon nitride achieves efficient photoreduction of O2 to H2O2 and highly selective photooxidization of C2H5OH simultaneously.

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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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