Remedying Defects in Carbon Nitride To Improve both Photooxidation and H2 Generation Efficiencies

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• 作者：Wenting Wu ; Jinqiang Zhang ; Weiyu Fan ; Zhongtao Li ; Lizhuo Wang ; Xiaoming Li ; Yang Wang ; Ruiqin Wang ; Jingtang Zheng ; Mingbo Wu ; Haibo Zeng
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：May 6, 2016
• 年：2016
• 卷：6
• 期：5
• 页码：3365-3371
• 全文大小：461K
• 年卷期：0
• ISSN：2155-5435

文摘

The outstanding visible light response of carbon nitride has aroused intense expectations regarding its photocatalysis, but it is impeded by the inevitable defects. Here, we report on a facile melamine-based defect-remedying strategy and resultant carbon nitride high-performance photocatalysts (R-C₃N₄). Melamine with amino groups and a triazine structure was selected as a “little patch” to passivate and remedy various defects inside carbon nitride. Such a remedying effect has been comprehensively proven by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analyses, and the ninhydrin test. In addition, their effects on photocatalysis were also individually confirmed by chemical methods, including cyano reduction reactions and deamination reactions. Furthermore, melamine remediation can result in g-C₃N₄/mpg-C₃N₄ junctions, which also favors electron transfer and charge separation during the photocatalytic reaction. In order to explore its broader applications, R-C₃N₄ was used as a photocatalyst for the photooxidation reaction of 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate (1,4-DHP) and simultaneous H₂ evolution. The conversion rates of 1,4-DHP and H₂ production catalyzed by R-C₃N₄ were enhanced 2 and 6.5 times, respectively. This rational design is beneficial for the conversion of 1,4-DHP during the preparation of bioactive compounds and clean hydrogen production at the same time.