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

2019 ◽  
Vol 9 (8) ◽  
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.

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

2018 ◽  
Vol 9 ◽  
pp. 353-363 ◽  
Author(s):  
Lan Ching Sim ◽  
Jing Lin Wong ◽  
Chen Hong Hak ◽  
Jun Yan Tai ◽  
Kah Hon Leong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Bisphenol A ◽  
Carbon Nitride ◽  
Separation Efficiency ◽  
Sugarcane Juice ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Dominant Factor ◽  
Spectroscopic Techniques ◽  
X Ray

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.

A Comparative Study on the Role of Precursors of Graphitic Carbon Nitrides for the Photocatalytic Degradation of Direct Red 81

2014 ◽  
Vol 807 ◽  
pp. 101-113 ◽  
Author(s):  
J. Theerthagiri ◽  
R.A. Senthil ◽  
J. Madhavan ◽  
B. Neppolian
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Carbon Nitride ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Nitrides

The graphitic carbon nitride (g-C3N4) materials have been synthesized from nitrogen rich precursors such as urea and thiourea by directly heating at 520 °C for 2 h. The as-synthesized carbon nitride samples were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) and particle size analysis. The photoelectrochemical measurements were performed using several on-off cycles under visible-light irradiation. The x-ray diffraction peak is broader which indicates the fine powder nature of the synthesized materials. The estimated crystallite size of carbon nitrides synthesized from urea (U-CN) and thiourea (T-CN) are 4.0 and 4.4 nm respectively. The particle size of U-CN and T-CN were analysed by particle size analyser and were found to be 57.3 and 273.3 nm respectively. The photocatalytic activity for the degradation of the textile dye namely, direct red-81 (DR81) using these carbon nitrides were carried out under visible light irradiation. In the present investigation, a comparison study on the carbon nitrides synthesized from cheap precursors such as urea and thiourea for the degradation of DR81 has been carried out. The results inferred that U-CN exhibited higher photocatalytic activity than T-CN. The photoelectrochemical studies confirmed that the (e--h+) charge carrier separation is more efficient in U-CN than that of T-CN and therefore showed high photocatalytic degradation. Further, the smaller particle size of U-CN is also responsible for the observed degradation trend.

Graphitic carbon nitride nanosheets with low ON1-doping content as an efficient photocatalyst for organic pollutants degradation

2021 ◽  
Author(s):  
Yan Huang ◽  
Lichao Ning ◽  
Zibo Feng ◽  
Guifeng Ma ◽  
Shuliang Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Organic Pollutants ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Doping Content ◽  
Excellent Photocatalytic Activity ◽  
The Common ◽  
Carbon Nitride Nanosheets

Oxygen-doped (O-doped) graphitic carbon nitride (g-C3N4) usually presents excellent photocatalytic activity than pristine g-C3N4 with the common ON2-doping. However, very few researches concerned about the ON1-doped g-C3N4. Herein, g-C3N4 nanosheets...

scholarly journals Development of ciprofloxacin sensor using iron-doped graphitic carbon nitride as transducer matrix: Analysis of ciprofloxacin in blood samples

2021 ◽  
Author(s):  
Hattna Shivarudraiah Vedhavathi ◽  
Ballur Prasanna Sanjay ◽  
Mahesh Basavaraju ◽  
Beejaganahalli Sangameshwara Madhukar ◽  
Ningappa Kumara Swamy
Keyword(s):  
Carbon Nitride ◽  
Electrochemical Impedance ◽  
Graphitic Carbon ◽  
Electrochemical Sensing ◽  
Graphitic Carbon Nitride ◽  
Matrix Analysis ◽  
Pencil Graphite Electrode ◽  
X Ray Diffraction ◽  
Standard Samples ◽  
X Ray

In the present work, we have synthesized an iron-decorated graphitic carbon nitride (Fe@g-C3N4) composite and employed it for electrochemical sensing of ciprofloxacin (CFX). The physicochemical characteristics of the Fe@g-C3N4 composite were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray diffraction (EDX) spectroscopy methods. Further, the pencil graphite electrode (PGE) was modified with Fe@g-C3N4 composite to get PGE/Fe@g-C3N4 electrode and characterized the resultant electrode by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Differential pulse voltammetry (DPV) was employed to determine the effect of concentration and interferents. The modified PGE/Fe@g-C3N4 electrode demonstrated the exceptional electrochemical performance for CFX identification and quantification with a LOD of 5.4 nM, a wide linear range of 0.001-1.0 µM, and high sensitivity of 0.0018 µA mM-1 cm-2. Besides, Fe@g-C3N4 modified PGE showed remarkable recovery results in qualitative analysis of CFX in human blood specimens. This research advocates that the Fe@g-C3N4 composite acts as an excellent transducer material in the electrochemical sensing of CFX in blood and standard samples. Further, the proposed strategy deduces that the PGE/Fe@g-C3N4 sensor can be a prospective candidate for the dynamic determination of CFX in blood serum and possibly ratified as an exceptional drug sensor for therapeutic purposes.

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

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650137 ◽  
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.

scholarly journals Enhancement of Photocatalytic Activity of ZnO/SiO2by Nanosized Pt for Photocatalytic Degradation of Phenol in Wastewater

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
R. M. Mohamed ◽  
M. A. Barakat
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Synthetic Wastewater ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ZnO- nanoparticles were synthesized by a sol-gel technique from and tetraethyl orthosilicate (TEOS). The synthesized samples were further modified by nanosized Pt from H2PtCl6solution through photoassisted deposition (PAD) and impregnation (Img) routes. The obtained samples were characterized by a series of techniques including X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy, N2adsorption, extended X-ray absorption fine structure (EXAFS), and transmission electron microscopy (TEM). The photocatalytic activity of the Pt-ZnO/ was evaluated by photocatalytic degradation of phenol in synthetic wastewater under UV-irradiation. Results obtained revealed that the surface area and the photocatalytic activity of the prepared samples were increased in the order ZnO/ < PAD: Pt-ZnO/ < img: Pt-ZnO/. The surface area decreased from 480 to 460 and 450 m2/g, while the efficiency of the phenol degradation increased from 80 to 85 and 100%, with the ZnO/, Img: Pt-ZnO-, and PAD: Pt-ZnO- samples, respectively.

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