Modulation of Lewis acidic-basic sites for efficient photocatalytic H2O2 production over potassium intercalated tri-s-triazine materials

[Display omitted] •K intercalated carbon nitride exhibits superior performance in photocatalytic H2O2 production.•Positive correlation between K contents and produced H2O2 concentrations was found.•Intercalated K atoms act as acidic sites for enhanced IPA adsorption and oxidation.•Strengthened basic...

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Bibliographic Details
Published in:Applied catalysis. B, Environmental Environmental, 2020-11, Vol.277, p.119225, Article 119225
Main Authors: Zhang, Jingzhen, Yu, Chunyang, Lang, Junyu, Zhou, Yongfeng, Zhou, Baoxue, Hu, Yun Hang, Long, Mingce
Format: Article
Language:English
Subjects:
Alcohols
Carbon
Carbon nitride
Chemisorption
Hydrogen peroxide
Isopropanol
K intercalation
Lewis acids
Oxidation
Photocatalysis
Polymers
Potassium
Protons
Triazine
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Summary:[Display omitted] •K intercalated carbon nitride exhibits superior performance in photocatalytic H2O2 production.•Positive correlation between K contents and produced H2O2 concentrations was found.•Intercalated K atoms act as acidic sites for enhanced IPA adsorption and oxidation.•Strengthened basicity of catalysts facilitates IPA deprotonation and O2 reduction. Photocatalytic H2O2 production (PHOP) on graphitic carbon nitride (GCN) at neutral pHs is limited by the sluggish oxidation of sacrificial alcohols and insufficient protons. In our work, the PHOP over a series of K intercalated triazine (KTCN) or tri-s-triazine units (KTTCN) reached 11–32 folds of GCN in the presence of only 0.5 vol% isopropanol, and a positive correlation between the H2O2 production and the K contents was found. The critical role of K was revealed as that K intercalation creates Lewis acidic sites for isopropanol adsorption and strengthens Lewis basic sites for hydrogen abstraction and proton release. The improved alcohol oxidation and enhanced O2 chemisorption synergistically result in dramatically accelerated PHOP over KTTCN. The findings provide the understanding of the preliminary active site dependent PHOP mechanism and bring insights for design of carbon nitride polymers with desirable photocatalytic performance.
ISSN:0926-3373
1873-3883
DOI:10.1016/j.apcatb.2020.119225