scholarly journals Fabrication of Covalently Linked Ruthenium Complex Onto Carbon Nitride Nanotubes For The Photocatalytic Degradation of Tetracycline Antibiotic

Author(s):  
Mohaddeseh Shahabi Nejad ◽  
Zahra Vakily ◽  
Ali Mostafavi ◽  
Hassan Sheibani

Abstract Due to the problem of direct disposal of effluents contains antibiotics to the environment and the emergence of resistant bacterial pathogens, the wastewater treatment of pharmaceutical industry has known as an importance research background. In this study, the refinement and photodegradation ability of one of the most widely used antibiotics, “tetracycline” was investigated by ruthenium complex immobilized on the modified graphitic carbon nitride nanotubes. For this purpose, graphitic carbon nitride nanotubes (g-C3N4 NTs) were successfully synthesized by the hydrothermal method and functionalized with 1,10-Phenantroline-5,6-dione ligand during another step. Then, the functionalized g-C3N4 NTs were reinforced with immobilization of dichloro(p-cymene)ruthenium(II) dimer. The structure and morphology of the prepared photocatalyst was studied by X-ray diffraction (XRD), fourier transform infrared (FT-IR), scanning, and transmission electron microscopy (SEM & TEM) analyses. In the following, the photocatalyst's ability to optically degrade the tetracycline antibiotics was performed in a suspension reactor equipped with a LED lamp (60 W) and effective parameters such as the amount of catalyst, irradiation time, temperature, and pH were optimized. The results showed that the immobilization of Ru complex onto functionalized g-C3N4 NTs improved the photocatalytic activity and increased the degradation efficiencies to amount 43%. Furthermore, COD analysis was used for the determination of the amount of mineralization and results showed that the mineralization of 10 mg/L tetracycline solution of about 90% can be performed using 20 mg of Ru (II) complex/ g-C3N4 NTs at pH=7 after 480 min without any additive oxidant.

2012 ◽  
Vol 518-523 ◽  
pp. 54-58 ◽  
Author(s):  
Chen Zhao ◽  
Si Yuan Yang ◽  
Zuo Tao Liu ◽  
Yue Ping Fang

A novel photocatalyst, AgCl loaded mesoporous graphitic carbon nitride (mpg-C3N4) in which silver chloride nanoparticles were introduced into the mesopores carbon nitride, was prepared by a dip-coating procedure. The as-prepared photocatalyst was characterized by X-ray diffraction, transmission electron microscopy, UV-visible spectrophotometry. The novel photocatalyst manifested a better photocatalytic activity than that of pure mpg-C3N4 for degradation of methyl orange.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2256
Author(s):  
Yanfei Wu ◽  
Jin Mao ◽  
Chuanwei Ao ◽  
Di Sun ◽  
Xiaorui Wang ◽  
...  

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.


2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Mohanna Zarei ◽  
Jamil Bahrami ◽  
Mohammad Zarei

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.


2020 ◽  
Vol 62 (4) ◽  
pp. 378-382
Author(s):  
Xuebing Hu ◽  
Yan Hu ◽  
Qing Zhang ◽  
Yun Yu ◽  
Yongqing Wang

Abstract Porous graphitic carbon nitride nanosheets were synthesized by the thermal condensation method using various precursors such as urea and melamine. Relevant properties of as-synthesized products were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and differential thermal analysis (DTA). The overall results suggest that the formation of porous graphitic carbon nitride nanosheets with a varied morphology can be achieved using diverse precursors through this process. Based on this product yield analysis, it is suggested that melamine and the lower synthesis temperature be selected to achieve the higher yield of graphitic carbon nitride production. The present work provides a facile and economic method for controlling the morphology and properties of graphitic carbon nitride products.


2018 ◽  
Vol 14 ◽  
pp. 1806-1812 ◽  
Author(s):  
Kazuhiko Maeda ◽  
Daehyeon An ◽  
Ryo Kuriki ◽  
Daling Lu ◽  
Osamu Ishitani

Graphitic carbon nitride (g-C3N4) was synthesized by heating urea at different temperatures (773–923 K) in air, and was examined as a photocatalyst for CO2 reduction. With increasing synthesis temperature, the conversion of urea into g-C3N4 was facilitated, as confirmed by X-ray diffraction, FTIR spectroscopy and elemental analysis. The as-synthesized g-C3N4 samples, further modified with Ag nanoparticles, were capable of reducing CO2 into formate under visible light (λ > 400 nm) in the presence of triethanolamine as an electron donor, with the aid of a molecular Ru(II) cocatalyst (RuP). The CO2 reduction activity was improved by increasing the synthesis temperature of g-C3N4, with the maximum activity obtained at 873–923 K. This trend was also consistent with that observed in photocatalytic H2 evolution using Pt-loaded g-C3N4. The photocatalytic activities of RuP/g-C3N4 for CO2 reduction and H2 evolution were thus shown to be strongly associated with the generation of the crystallized g-C3N4 phase.


Author(s):  
Hattna Shivarudraiah Vedhavathi ◽  
Ballur Prasanna Sanjay ◽  
Mahesh Basavaraju ◽  
Beejaganahalli Sangameshwara Madhukar ◽  
Ningappa Kumara Swamy

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.


2021 ◽  
Author(s):  
Pandiyarajan C ◽  
Rameshkumar Perumal ◽  
Murugesan S ◽  
Selvaraj M

Abstract Nitrobenzene (NB) is toxic even at low concentrations and hence, its contamination in the environment is a pervasive concern. The electrochemical techniques have emerged as rosy method to sense and degrade NB and graphitic carbon nitride (g-C3N4) catalysts are found to be promising for this. In this study, silver nanoparticles (AgNPs) decorated N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS) modified graphitic carbon nitride nanocomposites (EDAS/(g-C3N4-Ag)NC) having various silver concentrations are prepared through a facile method and applied for the electrochemical sensing of NB derivatives. UV-vis absorption edge at 430 nm together with a broad surface plasmon resonance (SPR) peak at 450 nm indicates the existence of AgNPs on the g-C3N4 nanosheets. FT-IR spectra endorse the presence of g-C3N4 nanosheets in the composite. The presence of Ag in EDAS/(g-C3N4-Ag)NC is confirmed by transmission electron microscopy, energy dispersive X-ray analysis and cyclic voltammetry (CV). The nanocomposite prepared with 2 mM Ag+ shows superb electrocatalytic activity towards the reduction of nitrobenzene and its derivatives. Sensitivity of the modified electrode and limit of detection (LOD) for NB assessed by square wave voltammetry are found to be 0.594 A M− 1 cm− 2 and 2 µM, respectively, in the linear range of 5–50 µM.


2020 ◽  
Vol 81 (9) ◽  
pp. 1840-1851 ◽  
Author(s):  
Jing Guo ◽  
Tao Chen ◽  
Xiaohui Zhou ◽  
Wenning Xia ◽  
Tao Zheng ◽  
...  

Abstract A novel composite (nZVI@K-GCN) was firstly synthesized by liquid phase reducing nanoscale zero-valent iron (nZVI) on potassium-doped graphitic carbon nitride (K-GCN). The results of Fourier transform infrared (FTIR) spectrometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) suggested that nZVI@K-GCN possessed abundant active functional groups such as terminal amino-groups (-NH or -NH2 groups) and -OH, and the specific surface area and pore volume from BET of nZVI@K-GCN were 4.7 times and 3.7 times higher than that of graphitic carbon nitride (GCN), respectively. These properties showed that the composite was especially suitable for heavy metal treatment. The application of the composite in the removal of chromium(VI) from aqueous solution showed that the maximum adsorption capacity of nZVI@K-GCN towards Cr(VI) was 68.6 mg/g at 308 K when the initial concentration of Cr(VI) was 30 mg/L, and more than 99% removal was obtained at pH = 3. This adsorption was an endothermic and spontaneous process. XPS patterns and batch experiments proved that complexation, electrostatic attraction and reduction precipitation were the main adsorption mechanism for Cr(VI) on nZVI@K-GCN.


Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4529 ◽  
Author(s):  
Dimitrios A. Giannakoudakis ◽  
Teresa J. Bandosz

Composite of two MOFs, copper-based Cu-BTC (HKUST-1) and zirconium-based Zr-BDC (UiO-66), with oxidized graphitic carbon nitride nanospheres were synthesized. For comparison, pure MOFs were also obtained. The surface features were analyzed using x-ray diffraction (XRD), sorption of nitrogen, thermal analysis, and scanning electron microscopy (SEM). The incorporation of oxidized g-C3N4 to the Cu-BTC framework caused the formation of a heterogeneous material of a hierarchical pores structure, but a decreased surface area when compared to that of the parent MOF. In the case of UiO-66, functionalized nanospheres were acting as seeds around which the crystals grew. Even though the MOF phases were detected in both materials, the porosity analysis indicated that in the case of Cu-BTC, a collapsed MOF/nonporous and amorphous matter was also present and the MOF phase was more defectous than that in the case of UiO-66. The results suggested different roles of oxidized g-C3N4 during the composite synthesis, depending on the MOF geometry. While spherical units of UiO-66 grew undisturbed around oxidized and spherical g-C3N4, octahedral Cu-BTC units experienced geometrical constraints, leading to more defects, a disturbed growth of the MOF phase, and to the formation of mesopores at the contacts between the spheres and MOF units. The differences in the amounts of CO2 adsorbed between the MOFs and the composites confirm the proposed role of oxidized g-C3N4 in the composite formation.


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