Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

Carbon dots (CDs) and graphitic carbon nitride (g-C3N4) composites (CD/g-C3N4) were successfully synthesized by a hydrothermal method using urea and sugarcane juice as starting materials. The chemical composition, morphological structure and optical properties of the composites and CDs were characterized using various spectroscopic techniques as well as transmission electron microscopy. X-ray photoelectron spectroscopy (XPS) results revealed new signals for carbonyl and carboxyl groups originating from the CDs in CD/g-C3N4 composites while X-ray diffraction (XRD) results showed distortion of the host matrix after incorporating CDs into g-C3N4. Both analyses signified the interaction between g-C3N4 and CDs. The photoluminescence (PL) analysis indicated that the presence of too many CDs will create trap states at the CD/g-C3N4 interface, decelerating the electron (e−) transport. However, the CD/g-C3N4(0.5) composite with the highest coverage of CDs still achieved the best bisphenol A (BPA) degradation rate at 3.87 times higher than that of g-C3N4. Hence, the charge separation efficiency should not be one of the main factors responsible for the enhancement of the photocatalytic activity of CD/g-C3N4. Instead, the light absorption capability was the dominant factor since the photoreactivity correlated well with the ultraviolet–visible diffuse reflectance spectra (UV–vis DRS) results. Although the CDs did not display upconversion photoluminescence (UCPL) properties, the π-conjugated CDs served as a photosensitizer (like organic dyes) to sensitize g-C3N4 and injected electrons to the conduction band (CB) of g-C3N4, resulting in the extended absorption spectrum from the visible to the near-infrared (NIR) region. This extended spectral absorption allows for the generation of more electrons for the enhancement of BPA degradation. It was determined that the reactive radical species responsible for the photocatalytic activity were the superoxide anion radical (O2 •−) and holes (h+) after performing multiple scavenging tests.

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Facile Synthesis of Fluorine Doped Graphitic Carbon Nitride with Enhanced Visible Light Photocatalytic Activity

NANO ◽

10.1142/s179329201650137x ◽

2016 ◽

Vol 11 (12) ◽

pp. 1650137 ◽

Cited By ~ 11

Author(s):

Mengqiu Xu ◽

Bo Chai ◽

Juntao Yan ◽

Haibo Wang ◽

Zhandong Ren ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Carbon Nitride ◽

Separation Efficiency ◽

Nitrogen Adsorption ◽

Active Species ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

X Ray

Fluorine doped graphitic carbon nitride (g-C3N4) was successfully synthesized by a convenient co-polycondensation of urea and ammonium fluoride (NH4F) mixtures, and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (FTIR), UV-Vis diffuse reflectance absorption spectra (UV-DRS), nitrogen adsorption–desorption, photoelectrochemical measurement and photoluminescence (PL) spectra. The photocatalytic activities of fluorine doped g-C3N4 samples were evaluated by the degradation of Rhodamine B (RhB) solution under visible light irradiation. The results showed that the fluorine doped g-C3N4 had a better photocatalytic activity than that of undoped g-C3N4, which was attributed to the favorable textural, optical and electronic properties derived from the fluorine atoms substituting nitrogen atoms of g-C3N4 frameworks. The photoelectrochemical measurements confirmed that the charges separation efficiency was improved by fluorine doping g-C3N4. Moreover, the tests of radical scavengers demonstrated that the holes (h[Formula: see text]) and superoxide radicals ([Formula: see text]O[Formula: see text]) were the main active species for the degradation of RhB.

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Zirconia nanoparticle-modified graphitic carbon nitride nanosheets for effective photocatalytic degradation of 4-nitrophenol in water

Applied Water Science ◽

10.1007/s13201-019-1076-8 ◽

2019 ◽

Vol 9 (8) ◽

Cited By ~ 5

Author(s):

Mohanna Zarei ◽

Jamil Bahrami ◽

Mohammad Zarei

Keyword(s):

Photocatalytic Activity ◽

Photocatalytic Degradation ◽

Carbon Nitride ◽

Diffuse Reflectance Spectroscopy ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

X Ray Diffraction ◽

X Ray ◽

Zirconia Nanoparticle ◽

Carbon Nitride Nanosheets

Abstract Zirconia (ZrO2)-modified graphitic carbon nitride (g-C3N4) nanocomposite was used for effective photodegradation of 4-nitrophenol (4-NP) in water. The ZrO2 nanoparticles, g-C3N4 nanosheets, and ZrO2/g-C3N4 nanocomposite were well characterized by including N2 adsorption, X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, UV–Vis diffuse reflectance spectroscopy, photoelectrochemical measurements, and photoluminescence spectroscopy methods. ZrO2/g-C3N4 nanocomposites were formed at room temperature using sonication and used for effective for photodegradation of 4-NP under irradiation with visible light. The nanocomposite samples resulted in a significant increase in photocatalytic activity compared with single-component samples of g-C3N4. In particular, the ZrO2/g-C3N4 nanocomposite exhibited the significant increase in the photocatalytic activity. The ZrO2/g-C3N4 nanocomposite showed an excellent catalytic activity toward the reduction of 4-NP in aqueous medium. Further, ZrO2/g-C3N4 nanocomposite can be reused several times for photocatalytic degradation as well as for 4-NP adsorption.

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Fast and Sensitive Detection of Bisphenol A and 4-n-Octylphenol in Foods Based on a 2D Graphitic Carbon Nitride (g-C3N4)/Gold Nano-Composite Film

Chemistry Africa ◽

10.1007/s42250-021-00227-x ◽

2021 ◽

Author(s):

Miaomiao Zou ◽

Suyan Zou ◽

Chunyan Hu ◽

Xiaoyun Lin ◽

Yongnian Ni

Keyword(s):

Bisphenol A ◽

Composite Film ◽

Carbon Nitride ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Sensitive Detection ◽

Nano Composite

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Band Engineering and Morphology Control of Oxygen-Incorporated Graphitic Carbon Nitride Porous Nanosheets for Highly Efficient Photocatalytic Hydrogen Evolution

Nano-Micro Letters ◽

10.1007/s40820-020-00571-6 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Yunyan Wu ◽

Pan Xiong ◽

Jianchun Wu ◽

Zengliang Huang ◽

Jingwen Sun ◽

...

Keyword(s):

Surface Area ◽

Hydrogen Evolution ◽

Carbon Nitride ◽

Separation Efficiency ◽

Physical Adsorption ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Photocatalytic Hydrogen Evolution ◽

Band Engineering ◽

Highly Efficient

AbstractGraphitic carbon nitride (g-C3N4)-based photocatalysts have shown great potential in the splitting of water. However, the intrinsic drawbacks of g-C3N4, such as low surface area, poor diffusion, and charge separation efficiency, remain as the bottleneck to achieve highly efficient hydrogen evolution. Here, a hollow oxygen-incorporated g-C3N4 nanosheet (OCN) with an improved surface area of 148.5 m2 g−1 is fabricated by the multiple thermal treatments under the N2/O2 atmosphere, wherein the C–O bonds are formed through two ways of physical adsorption and doping. The physical characterization and theoretical calculation indicate that the O-adsorption can promote the generation of defects, leading to the formation of hollow morphology, while the O-doping results in reduced band gap of g-C3N4. The optimized OCN shows an excellent photocatalytic hydrogen evolution activity of 3519.6 μmol g−1 h−1 for ~ 20 h, which is over four times higher than that of g-C3N4 (850.1 μmol g−1 h−1) and outperforms most of the reported g-C3N4 catalysts.

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