scholarly journals Graphitic Carbon Nitride as an Amplification Platform on an Electrochemical Paper-Based Device for the Detection of Norovirus-Specific DNA

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2070 ◽  
Author(s):  
Aditya Rana ◽  
Manjari Killa ◽  
Neelam Yadav ◽  
Annu Mishra ◽  
Ashish Mathur ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Capture Probe ◽  
X Ray ◽  
Vis Spectroscopy

Norovirus is one of the leading causes of gastroenteritis, acute vomiting, intense diarrhoea, acute pain in the stomach, high fever, headaches, and body pain. Conventional methods of detection gave us very promising results but had disadvantages such as low sensitivity, cost ineffectiveness, reduced specificity and selectivity, etc. Therefore, biosensors can be a viable alternative device which can overcome all setbacks associated with the conventional method. An electrochemical sensor based on oxidized graphitic carbon nitride (Ox-g-C3N4) modified electrochemical paper-based analytical device (ePAD) was fabricated for the detection of norovirus DNA. The synthesized Ox-g-C3N4 nanosheets were characterized by field emission scanning electron microscopy (FESEM), X-ray Diffraction (XRD), UV-Vis spectroscopy and X-Ray Photoelectron Spectroscopy. The capture probe DNA (PDNA) modified electrodes were characterized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). These two characterization techniques were also employed to find the optimal scan rate, response time and temperature of the fabricated sensor. The fabricated biosensor showed a limit of detection (LOD) of 100 fM. Furthermore, the specificity of the reported biosensor was affirmed by testing the response of capture probe DNA with oxidized graphitic carbon nitride (PDNA/Ox-g-C3N4) modified ePAD on the introduction of a non-complimentary DNA. The fabricated ePAD sensor is easy to fabricate, cost effective and specific, and requires a minimum analysis time of 5 s.

scholarly journals Influence of High Temperature Synthesis on the Structure of Graphitic Carbon Nitride and Its Hydrogen Generation Ability

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2756 ◽  
Author(s):  
Emilia Alwin ◽  
Kamila Kočí ◽  
Robert Wojcieszak ◽  
Michał Zieliński ◽  
Miroslava Edelmannová ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Hydrogen Generation ◽  
Thermal Polymerization ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Photocatalytic Decomposition ◽  
Heating Rates ◽  
X Ray ◽  
Synthesis Conditions

Graphitic carbon nitride (g-C3N4) was obtained by thermal polymerization of dicyandiamide, thiourea or melamine at high temperatures (550 and 600 °C), using different heating rates (2 or 10 °C min−1) and synthesis times (0 or 4 h). The effects of the synthesis conditions and type of the precursor on the efficiency of g-C3N4 were studied. The most efficient was the synthesis from dicyandiamide, 53%, while the efficiency in the process of synthesis from melamine and thiourea were much smaller, 26% and 11%, respectively. On the basis of the results provided by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), thermogravimetric analysis (TGA), elemental analysis (EA), the best precursor and the optimum conditions of synthesis of g-C3N4 were identified to get the product of the most stable structure, the highest degree of ordering and condensation of structure and finally the highest photocatalytic activity. It was found that as the proton concentration decreased and the degree of condensation increased, the hydrogen yields during the photocatalytic decomposition of water–methanol solution were significantly enhanced. The generation of hydrogen was 1200 µmol g−1 and the selectivity towards hydrogen of more than 98%.

Two-Dimensional WS2/g-C3N4 Layered Heterostructures With Enhanced Pseudocapacitive and Electrocatalytic Properties

2020 ◽  
Author(s):  
Oluwafunmilola Ola ◽  
Yanqiu Zhu
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Hybrid Nanocomposites ◽  
Graphitic Carbon Nitride ◽  
Electrochemical Performances ◽  
X Ray

Abstract In this work, tungsten-based hybrid nanocomposites were grown on interconnected, macroscopic graphitic carbon nitride scaffold after solvothermal treatment followed by sulfidation to attain multifunctional composite electrocatalysts. The physicochemical properties of the obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The tungsten-based composites were tested as electrodes for pseudocapacitors and as electrocatalysts for hydrogen evolution reaction, to take advantage of their porous graphitic carbon nitride features which would be beneficial for optimal ion transport to tungsten-based nanoparticles. These unique physicochemical features endow these composites with excellent electrochemical performances to reach a current density of 10 mA/cm2 for the hydrogen evolution reaction. In addition to demonstrating excellent specific capacitance, these hybrid nanocomposites also possess good stability after 8 hours of testing.

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 Facile Synthesis of Phosphorus and Cobalt Co-Doped Graphitic Carbon Nitride for Fire and Smoke Suppressions of Polylactide Composite

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1106 ◽  
Author(s):  
Xianwu Cao ◽  
Xiaoning Chi ◽  
Xueqin Deng ◽  
Qijun Sun ◽  
Xianjing Gong ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Co2 Production ◽  
Dimensional Structure ◽  
X Ray ◽  
Co Doped

Due to the unique two-dimensional structure and features of graphitic carbon nitride (g-C3N4), such as high thermal stability and superior catalytic property, it is considered to be a promising flame retardant nano-additive for polymers. Here, we reported a facile strategy to prepare cobalt/phosphorus co-doped graphitic carbon nitride (Co/P-C3N4) by a simple and scalable thermal decomposition method. The structure of Co/P-C3N4 was confirmed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The carbon atoms in g-C3N4 were most likely substituted by phosphorous atoms. The thermal stability of polylactide (PLA) composites was increased continuously with increasing the content of Co/P-C3N4. In contrast to the g-C3N4, the Polylactide (PLA) composites containing Co/P-C3N4 exhibited better flame retardant efficiency and smoke suppression. With the addition of 10 wt % Co/P-C3N4, the peak heat release rate (PHRR), carbon dioxide (CO2) production (PCO2P) and carbon oxide (CO) production (PCOP) values of PLA composites decreased by 22.4%, 16.2%, and 38.5%, respectively, compared to those of pure PLA, although the tensile strength of PLA composites had a slightly decrease. The char residues of Co/P-C3N4 composites had a more compact and continuous structure with few cracks. These improvements are ascribed to the physical barrier effect, as well as catalytic effects of Co/P-C3N4, which inhibit the rapid release of combustible gaseous products and suppression of toxic gases, i.e., CO.

scholarly journals Ultrasound assisted Fenton-like degradation of dyes using copper doped graphitic carbon nitride

2021 ◽  
Author(s):  
Chongqing Wang ◽  
Rong Huang ◽  
Ruirui Sun ◽  
Hui Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Catalytic Mechanism ◽  
Dye Degradation ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Order Kinetic ◽  
Acid Orange 7 ◽  
Solution Ph ◽  
X Ray

Abstract A novel copper doped graphitic carbon nitride (Cu-C3N4) was successfully synthesized and used as an effective Fenton-like catalyst. Cu-C3N4 was characterized by scanning electron microscopy, surface area analyzer, Fourier transform infrared spectroscopy, X-ray diffractometer, and X-ray photoelectron spectroscopy. Effect of process parameters including catalyst dosage, hydrogen peroxide (H2O2) concentration, solution pH, and initial methylene blue (MB) concentration was investigated to evaluate catalytic performance. The pseudo first-order kinetic model was used to describe the catalytic process. The enhancement of MB degradation is observed assisted by ultrasound. MB degradation of 96% is obtained within 30 min in Cu-C3N4/H2O2/ultrasound system, and the corresponding rate constant is 0.099 min−1. Effective MB degradation is obtained over a broad pH range (3.3–9.9). The catalytic mechanism is examined by ultraviolet-visible spectra, quenching test, and electron spin resonance determination. The dominant mechanism of MB degradation is ascribed to the ultrasonic H2O2 activation by Cu-C3N4 for hydroxyl radical generation. Cu-C3N4 has good reusability and is effective to degrade rhodamine B and acid orange 7. This work not only contributes to the field of wastewater treatment, but also provides insights into the synthesis of Fenton-like catalysts. The results manifest that Cu-C3N4 is a promising Fenton-like catalyst for dye degradation in the field of environmental pollution remediation.

scholarly journals Elucidating the structure of the graphitic carbon nitride nanomaterials via X-ray photoelectron spectroscopy and X-ray powder diffraction techniques

2020 ◽  
Vol 49 (36) ◽  
pp. 12805-12813
Author(s):  
Emilia Alwin ◽  
Waldemar Nowicki ◽  
Robert Wojcieszak ◽  
Michał Zieliński ◽  
Mariusz Pietrowski
Keyword(s):  
Powder Diffraction ◽  
Layered Structure ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
X Ray

Elucidating the layered structure of the g-C3N4 nanomaterials using X-ray photoelectron spectroscopy and X-ray powder diffraction techniques is possible.

Graphitic carbon nitride (g-C3N4) as an efficient metal-free Fenton-like catalyst for degrading organic pollutants: the overlooked non-photocatalytic activity

2020 ◽  
Vol 81 (3) ◽  
pp. 518-528 ◽  
Author(s):  
G. X. Zhu ◽  
T. L. Lu ◽  
L. Han ◽  
Y. Z. Zhan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Catalytic Mechanism ◽  
Catalytic Performance ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Alkaline Condition ◽  
Weakly Alkaline ◽  
X Ray ◽  
Metal Free

Abstract Graphitic carbon nitride (g-C3N4) has attracted a large amount of research, mainly being used as a photocatalyst, but its Fenton-like catalytic performance has been overlooked. In this paper, the dark Fenton-like catalytic performance of g-C3N4 was evaluated by degrading rhodamine B over a wide pH range. The results showed that the g-C3N4, which was synthesized by conventional urea pyrolysis without any modification, was an efficient metal-free heterogeneous Fenton-like catalyst. The highest activity occurred under a weakly alkaline condition of about pH 10. The experiment of catalyst recycling indicated that g-C3N4 had long-term stability. The reactive oxidizing species of HO·, generated by the g-C3N4 activating H2O2, was identified by EPR and further supported by a scavenging experiment of HO· using isopropanol as the scavenger. The HNO3 oxidation of g-C3N4 resulted in catalytic deactivation, implying the catalytic activity originated from the surface reduced groups of g-C3N4. The structure of synthesized g-C3N4 before and after the HNO3 oxidation was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, and a possible catalytic mechanism was proposed.

scholarly journals Facile Preparation of Wormlike Graphitic Carbon Nitride for Photocatalytic Degradation of Ustiloxin A

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2256
Author(s):  
Yanfei Wu ◽  
Jin Mao ◽  
Chuanwei Ao ◽  
Di Sun ◽  
Xiaorui Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Human Reproduction ◽  
Graphitic Carbon Nitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
False Smut

Natural toxic contaminants have been recognized as threats to human health. Ustiloxins are the toxic secondary metabolites of fungus generated from rice false smut disease, which are harmful to animal/human reproduction and growth. However, there are rare researches on the control and reduction of ustiloxins through physical, chemical and biological ways. Herein, we demonstrated that photocatalysis of semiconductor nanomaterials could be as a potential way to degrade or mitigate the contamination of ustiloxin A. A kind of wormlike graphitic carbon nitride (g-C3N4) was facilely prepared from modified dicyandiamide precursor via pyrolysis method and characterized by X-ray diffraction, high-resolution transmission electron microscope and X-ray photoelectron spectroscopy etc. It was found that g-C3N4 from modified dicyandiamide precursor showed better activity for ustiloxin A degradation under visible light irradiation than that of pristine g-C3N4. This was ascribed to the lager specific surface area, more uniform microstructure, better photogenerated charges separation and transformation of wormlike g-C3N4 compared with pristine g-C3N4. Most important, the structure of degradation intermediates and the possible pathway were proposed based on the results of high-performance liquid chromatography-mass spectrometry after 80 min photoreaction treatment. Our findings may provide a green, efficient way for ustiloxins mitigation and useful information for future study.

Graphitic carbon nitride modified with Pd nanoparticles toward efficient cathode catalyst for Li-O2 batteries

2020 ◽  
Vol 13 (07) ◽  
pp. 2051045
Author(s):  
Kaicheng Yue ◽  
Zhaoqian Yan ◽  
Zhihao Sun ◽  
Anran Li ◽  
Lei Qian
Keyword(s):  
Electron Microscope ◽  
Current Density ◽  
Carbon Nitride ◽  
Specific Capacity ◽  
Pd Nanoparticles ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Cathode Catalyst ◽  
X Ray ◽  
Cathode Catalysts

In this work, graphitic carbon nitride (g-C3N4) was modified by Pd nanoparticles (Pd-CN) to prepare an efficient cathode catalyst for Li-O2 batteries. The specific surface area of g-C3N4 was improved to 239.56[Formula: see text]m2/g by two-steps thermal polymerization. Pd nanoparticles were loaded onto the g-C3N4 by K2PdCl4 reduction with NaBH4. The resulted Pd-CN composites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscope, and transmission electron microscope. The results proved that g-C3N4 showed three-dimensional layered and porous structure, and Pd nanoparticles were successfully supported on it. The Li-O2 batteries using Pd-CN composites as cathode catalysts were assembled and tested. The maximum initial discharge specific capacity reached 26,614[Formula: see text]mAh[Formula: see text]g[Formula: see text] at current density of 100[Formula: see text]mA[Formula: see text]g[Formula: see text]. The electrodes remained large capacity under high current density, meaning excellent rate capability. Li-O2 batteries containing Pd-CN cathode were continuously cycled for 70 cycles with no loss of capacity and obvious change in the terminal voltage. These electrochemical results indicated that the loading Pd nanoparticles effectively increased specific capacity, reduced overpotential and improved the cyclic stability. The Pd-CN composites are proved to be the promising cathode catalysts for Li-O2 batteries.

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.

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