Oxygen and methyl co-modified carbon nitride for enhanced photocatalytic dagradation

Abstract Carbon nitride (C3N4) is a promising photocatalytic material to degrade various pollutants. However, the degradation activity is restricted by the limited light absorption and fast recombination of photoinduced carriers. Herein, a structure modification strategy by introducing a functional reagent during the polymerization process was adopted. The structure, composition and morphology of prepared materials were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. Benefiting from the implantation of oxygen and methyl groups in triazine unit of C3N4, enhanced light absorption and effective carrier separation are achieved. As a result, the modified C3N4 exhibits a significant enhanced degradation activity and the optimal rate constant of modified C3N4 for Acid Red 9 degradation is 5.83 times that of pristine C3N4. The work demonstrates the effect of structure modification in C3N4 for enhancing degradation activity.

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Effect of Gaseous Medium Pressure on Plasmadynamic Synthesis Product in the C-N System with Melamine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1040.813 ◽

2014 ◽

Vol 1040 ◽

pp. 813-818 ◽

Cited By ~ 8

Author(s):

I.I. Shanenkov ◽

Artur A. Sivkov ◽

А.Ya. Pak ◽

Yu.L. Kolganova

Keyword(s):

Photoelectron Spectroscopy ◽

Carbon Nitride ◽

Gaseous Medium ◽

Morphological Changes ◽

Nitrogen Pressure ◽

Synthesis Product ◽

X Ray Diffraction ◽

Capacitive Energy Storage ◽

X Ray ◽

Transmission Electron

The possibility of plasmodynamic synthesis in the carbon-nitrogen system when using melamine as a precursor is described in the paper. The system based on the capacitive energy storage, which allows simultaneously powering the two opposite-directed coaxial magnetoplasma accelerators, is developed. The effect of gaseous medium in the processing chamber of the system on the synthesis product is investigated by applying such techniques as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It is demonstrated that an increase in nitrogen pressure results in the structural and morphological changes in the synthesized sample, which might be caused by the increased carbon nitride yield and a great number of the appearing C-N bonds.

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Synthesis and Photocatalytic Activity of Fluorine DOPED-g-C3N4

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.889.24 ◽

2019 ◽

Vol 889 ◽

pp. 24-32 ◽

Cited By ~ 1

Author(s):

Nguyen Van Phuc ◽

Doan Tran An ◽

Nguyen Ngoc Tri ◽

Tran Huu Ha ◽

Tran Thi Thu Hien ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Carbon Nitride ◽

Diffuse Reflectance ◽

Dft Calculation ◽

Diffuse Reflectance Spectroscopy ◽

Weight Ratio ◽

Ammonium Fluoride ◽

X Ray Diffraction ◽

Photo Degradation ◽

X Ray

F-doped graphitic carbon nitride was synthesized via simple solid-state calcination of mixture with various weight ratios of urea, as precursor, and ammonium fluoride, as modifying agent. The obtained materials were characterized by a number of modern methods such as X-ray diffraction, Scanning electron microscopy, Infrared spectroscopy, Ultraviolet-visible diffuse reflectance spectroscopy, Thermo-gravimetry analysis, X-ray photoelectron spectroscopy, which all demonstrated the successful modification of g-C3N4 by fluorine. The experimental results illustrated that the doped sample, in which weight ratio of urea and ammonium fluoride equals 93:7 respectively, performs the highest photo-degradation efficiency of Rhodamine B up to 75 % after 7-hour visible light irradiation. The doping effect of fluorine on photo-catalytic activity of g-C3N4 was also discussed within supporting information of DFT calculation.

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Synthesis and Characterization of CdS/TiO2-Montmorillonite Nanocomposite with Enhanced Visible-Light Absorption

Journal of Spectroscopy ◽

10.1155/2014/961230 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Feng-shan Zhou ◽

Dai-mei Chen ◽

Bao-lin Cui ◽

Wei-heng Wang

Keyword(s):

Visible Light ◽

Light Absorption ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

Cds Nanoparticles ◽

X Ray Diffraction ◽

Visible Light Absorption ◽

X Ray ◽

Vis Spectroscopy ◽

Adsorption Desorption

Sodium montmorillonite (MMT) was chosen as the carrier; a serial of CdS/TiO2-MMT nanocomposites with enhanced visible-light absorption ability was prepared by hydrothermal synthesis method combination with semiconductor compound modification method. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy; the results showed that TiO2and CdS nanoparticles were loaded on the surface of montmorillonite uniformly. N2adsorption-desorption experiment showed that the specific surface area of TiO2/montmorillonite nanocomposite made by this method can reach 200 m2/g and pore-size distribution was from 4 to 6 nm; UV-Vis showed that the recombination of CdS and TiO2enhanced visible-light absorption ability of samples of TiO2/montmorillonite and visible-light absorption ability increase with the increased of the adsorption of CdS.

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Dye-Sensitized-Assisted, Enhanced Photocatalytic Activity of TiO2/Bi4V2O11

NANO ◽

10.1142/s1793292018500285 ◽

2018 ◽

Vol 13 (03) ◽

pp. 1850028 ◽

Cited By ~ 4

Author(s):

Mengjun Liang ◽

Zhiyuan Yang ◽

Ying Mei ◽

Haoran Zhou ◽

Shuijin Yang

Keyword(s):

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

X Ray Diffraction ◽

X Ray ◽

Dye Sensitized ◽

Transmission Electron ◽

Efficient Charge ◽

Degradation Activity ◽

Adsorption Desorption

In this study, the TiO2/Bi4V2O[Formula: see text] nanocomposite photocatalysts were prepared by loading different amount of TiO2 nanoparticles onto the surface of Bi4V2O[Formula: see text] nanospheres via a facile hydrothermal method. Afterwards, the as-synthesized samples were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), N2 adsorption–desorption isotherms, X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS) and photocurrent techniques. The optimal TiO2/Bi4V2O[Formula: see text] composite with 20[Formula: see text]wt.% TiO2 loading (TB2) exhibited the best photocatalytic activity, which could degrade almost RhB completely within 30[Formula: see text]min under visible light irradiation. The enhanced photocatalytic activity of TiO2/Bi4V2O[Formula: see text] composites for RhB degradation could be mainly ascribed to the efficient charge separation over dye-induced sensitized and the increased specific surface area. Also, the photocatalytic activities of TiO2/Bi4V2O[Formula: see text] for CIP degradation were tested. After five consecutive recycling experiments, the photocatalytic degradation activity of TB2 could still reach 99% which indicated that the catalysts had superior stability. Based on the experimental and bandgap calculations, a possible photocatalytic mechanism of TiO2/Bi4V2O[Formula: see text] for RhB degradation was proposed.

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Synthesis, Characterization and Photocatalytic Activity of MoS2/ZnSe Heterostructures for the Degradation of Levofloxacin

Catalysts ◽

10.3390/catal10121380 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1380

Author(s):

Effat Sitara ◽

Muhammad Fahad Ehsan ◽

Habib Nasir ◽

Sadia Iram ◽

Syeda Aqsa Batool Bukhari

Keyword(s):

Visible Light ◽

Photoelectron Spectroscopy ◽

Catalytic Performance ◽

Reflectance Spectroscopy ◽

New Materials ◽

X Ray Diffraction ◽

X Ray ◽

Degradation Activity ◽

Antibiotic Degradation

Antibiotics have been extensively used over the last few decades. Due to their extensive usage and persistence in the environment, they are considered as emergent pollutants. It is, therefore, important to synthesize new materials for efficient antibiotic degradation. Herein, we report the MoS2/ZnSe heterostructures prepared by a simple ultrasonication method. Heterostructures were prepared with different ratios of MoS2 and ZnSe, i.e., 1:3, 1:1 and 3:1. Characterization of the heterostructures was done by UV-vis diffused reflectance spectroscopy (UV-vis-DRS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and photoluminescence (PL) techniques to understand the morphology and surface chemistry. The results show that an efficient interface was formed to harness the visible light and degrade levofloxacin, which was monitored by gradual decreases in the UV-vis absorbance signal of levofloxacin. Among the prepared heterostructures and their pure counter parts, MoS2/ZnSe 3:1 (3:1 MZ) showed a better degradation activity of 73.2% as compared to pure MoS2 (29%) and ZnSe (17.1%) in the presence of visible light in a time span of two hours. The reusability studies showed that the catalytic performance of 3:1 MZ did not decrease significantly after three cycles. Moreover, the morphology and the crystal structure also remained unchanged.

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

Nanomaterials ◽

10.3390/nano10112256 ◽

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.

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Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

MRS Proceedings ◽

10.1557/proc-780-y5.5 ◽

2003 ◽

Vol 780 ◽

Author(s):

C. Essary ◽

V. Craciun ◽

J. M. Howard ◽

R. K. Singh

Keyword(s):

Uv Radiation ◽

Photoelectron Spectroscopy ◽

Grazing Angle ◽

X Ray Diffraction ◽

Metal Thin Films ◽

X Ray ◽

Force Microscopy ◽

Si Substrates ◽

Atomic Force ◽

Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

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α-Cellulose Fibers of Paper-Waste Origin Surface-Modified with Fe3O4 and Thiolated-Chitosan for Efficacious Immobilization of Laccase

Polymers ◽

10.3390/polym13040581 ◽

2021 ◽

Vol 13 (4) ◽

pp. 581

Author(s):

Gajanan S. Ghodake ◽

Surendra K. Shinde ◽

Ganesh D. Saratale ◽

Rijuta G. Saratale ◽

Min Kim ◽

...

Keyword(s):

Enzyme Immobilization ◽

Photoelectron Spectroscopy ◽

Cellulose Fibers ◽

Relative Activity ◽

Significant Activity ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Laccase Immobilization ◽

Surface Modified

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.

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Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽

10.3390/catal11030346 ◽

2021 ◽

Vol 11 (3) ◽

pp. 346

Author(s):

Sonam Goyal ◽

Maizatul Shima Shaharun ◽

Ganaga Suriya Jayabal ◽

Chong Fai Kait ◽

Bawadi Abdullah ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Catalyst Support ◽

Oxidation Potential ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Molar Ratios ◽

Optimum Parameters ◽

Reduction Of Co2 ◽

Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

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Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽

10.3390/coatings11080937 ◽

2021 ◽

Vol 11 (8) ◽

pp. 937

Author(s):

Yingying Hu ◽

Md Rasadujjaman ◽

Yanrong Wang ◽

Jing Zhang ◽

Jiang Yan ◽

...

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Photoelectron Spectroscopy ◽

Crystal Size ◽

Silicon Substrates ◽

X Ray Diffraction ◽

Dc Magnetron Sputtering ◽

Flow Rates ◽

X Ray ◽

N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

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