Photocatalytic Degradation of 2-chlorophenol under γ-Bi2MoO6/Graphene Oxide

MRS Advances ◽  
2019 ◽  
Vol 5 (11) ◽  
pp. 581-589 ◽  
Author(s):  
J. Rodríguez-López ◽  
R. Rangel ◽  
P. Bartolo-Pérez ◽  
J.J. Alvarado-Gil ◽  
J. L. Cervantes-López ◽  
...  

ABSTRACTThe present research was aimed to study the degradation of 2-Chlorophenol through the use of bismuth molybdate (γ-Bi2MoO6) structures supported on graphene oxide (GO) which is intended to control the recombination of charge carriers. γ-Bi2MoO6/GO systems were doped with nitrogen via chemical reaction, to reduce their energy gap, improving their photocatalytic activity. Structural and physicochemical characterization of the resulting catalysts were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis. The obtained compounds show good photo catalytic performance when using visible energy to degrade 2-Chlorophenol, obtaining 80% of degradation in 65 min.

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 777 ◽  
Author(s):  
Yang Gong ◽  
Yingchun Yu ◽  
Huixuan Kang ◽  
Xiaohong Chen ◽  
Hao Liu ◽  
...  

Chitosan, a semi-crystalline biomolecule, has attracted wide attention due to its high synthesis flexibility. In this study, to improve the mechanical properties of chitosan aerogels (CSAs), graphene oxide (GO) was extracted and introduced into chitosan aerogels as fillers. The porous CSAs/GO composite aerogels were fabricated by an environmentally friendly freeze-drying process with different GO contents (0, 0.5, 1.0, 1.5, wt.%). The characteristics of the CSAs/GO were investigated by scanning electron microscopy (SEM), mechanical measurements and mercury porosimeter. The crystallinity of samples was characterized by X-ray diffraction (XRD). The mechanism of the effect of graphene oxide on chitosan was studied by Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results show that the microstructure of the samples is developed in the network structure. The porosity of CSAs/GO aerogels is as high as 87.6%, and the tensile strength of the films increased from 6.60 MPa to 10.56 MPa with the recombination of graphene oxide. The crystallinity (CrI) of composite aerogels increased from 27% to 81%, which indicates that graphene oxide improves the mechanical properties of chitosan by chemical crosslinking.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 490
Author(s):  
María Montserrat Cruz-Benítez ◽  
Pablo Gónzalez-Morones ◽  
Ernesto Hernández-Hernández ◽  
José Roberto Villagómez-Ibarra ◽  
Javier Castro-Rosas ◽  
...  

In this work, we report the synthesis of graphene oxide (GO) nanohybrids with starch, fructose, and micro-cellulose molecules by sonication in an aqueous medium at 90 °C and a short reaction time (30 min). The final product was washed with solvents to extract the nanohybrids and separate them from the organic molecules not grafted onto the GO surface. Nanohybrids were chemically characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy and analyzed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). These results indicate that the ultrasound energy promoted a chemical reaction between GO and the organic molecules in a short time (30 min). The chemical characterization of these nanohybrids confirms their covalent bond, obtaining a grafting percentage above 40% the weight in these nanohybrids. This hybridization creates nanometric and millimetric nanohybrid particles. In addition, the grafted organic molecules can be crystallized on GO films. Interference in the ultrasound waves of starch hybrids is due to the increase in viscosity, leading to a partial hybridization of GO with starch.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1380
Author(s):  
Effat Sitara ◽  
Muhammad Fahad Ehsan ◽  
Habib Nasir ◽  
Sadia Iram ◽  
Syeda Aqsa Batool Bukhari

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.


Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3175
Author(s):  
Sabina Drewniak ◽  
Marcin Procek ◽  
Roksana Muzyka ◽  
Tadeusz Pustelny

In this study, the sensitivity of reduced graphene oxide structures (rGO) to the action of selected gases (especially hydrogen, but also nitrogen dioxide and ammonia) was examined. Two sensing structures, based on rGO structures, obtained by different methods of oxidation (the modified Hummers, and the modified Tour’s method respectively), were investigated. We show here that the method used for the oxidation of rGO influences the sensitivity of the sensing structure during contact with various gaseous atmospheres. We performed our experiments in the atmosphere, containing hydrogen in a concentration range from 0 to 4% in nitrogen or synthetic air, both in dry and wet conditions. The temperature range was from 50 °C to 190 °C. Finally, we checked how the resistance of the samples changes when the other gases (NO2, NH3) appear in tested gas mixtures. The gas investigations were supplemented by the characterization of rGOs materials using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N2 sorption method.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
YiChao Yan ◽  
Wei Shi ◽  
HongChuan Jiang ◽  
Jie Xiong ◽  
WanLi Zhang ◽  
...  

The redox reaction between Al and metallic oxide has its advantage compared with intermetallic reaction and Al/NiO nanomutlilayers are a promising candidate for enhancing the performance of energetic igniter. Al/NiO nanomutlilayers with different modulation periods are prepared on alumina substrate by direct current (DC) magnetron sputtering. The thicknesses of each period are 250 nm, 500 nm, 750 nm, 1000 nm, and 1500 nm, respectively, and the total thickness is 3 μm. The X-ray diffraction (XRD) and scanning electron microscope (SEM) results of the as-deposited Al/NiO nanomutlilayers show that the NiO films are amorphous and the layered structures are clearly distinguished. The X-ray photoelectron spectroscopy (XPS) demonstrates that the thickness of Al2O3increases on the side of Al monolayer after annealing at 450°C. The thermal diffusion time becomes greater significantly as the amount of thermal boundary conductance across the interfaces increases with relatively smaller modulation period. Differential scanning calorimeter (DSC) curve suggests that the energy release per unit mass is below the theoretical heat of the reaction due to the nonstoichiometric ratio between Al and NiO and the presence of impurities.


2012 ◽  
Vol 48 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Noely Camila Tavares Cavalcanti ◽  
Giovana Damasceno Sousa ◽  
Maria Alice Maciel Tabosa ◽  
José Lamartine Soares Sobrinho ◽  
Leila Bastos Leal ◽  
...  

The aim of this study was to characterize three batches of albendazole by pharmacopeial and complementary analytical techniques in order to establish more detailed specifications for the development of pharmaceutical forms. The ABZ01, ABZ02, and ABZ03 batches had melting points of 208 ºC, 208 ºC, and 209 ºC, respectively. X-ray diffraction revealed that all three batches showed crystalline behavior and the absence of polymorphism. Scanning electron microscopy showed that all the samples were crystals of different sizes with a strong tendency to aggregate. The samples were insoluble in water (5.07, 4.27, and 4.52 mg mL-1, respectively) and very slightly soluble in 0.1 M HCl (55.10, 56.90, and 61.70 mg mL-1, respectively) and additionally showed purities within the range specified by the Brazilian Pharmacopoeia 5th edition (F. Bras. V; 98% to 102%). The pharmacopeial assay method was not reproducible and some changes were necessary. The method was validated and showed to be selective, specific, linear, robust, precise, and accurate. From this characterization, we concluded that pharmacopeial techniques alone are not able to detect subtle differences in active pharmaceutical ingredients; therefore, the use of other complementary techniques is required to ensure strict quality control in the pharmaceutical industry.


2013 ◽  
Vol 873 ◽  
pp. 152-157
Author(s):  
Long Long Chen ◽  
Jun Ming Li ◽  
Xiao Min Gong ◽  
Jian Li

Using a chemically induced transition in an FeCl2 solution, γ-Fe2O3 nanoparticles can be prepared from an amorphous precursor composed of FeOOH and Mg (OH)2. Surface modification by adding ZnCl2 during liquid-phase synthesis was attempted. The magnetization, morphology, crystal structure, and chemical species of as-prepared samples were characterized by vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray energy-dispersive spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the surface of the γ-Fe2O3 nanoparticles can be modified by adding ZnCl2 to form composite nanoparticles with a γ-Fe2O3/ZnFe2O4 ferrite core coated with Zn (OH)2 and absorbed FeCl36H2O; this modification can be enhanced by additional NaOH.


2013 ◽  
Vol 28 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Thomas N. Blanton ◽  
Debasis Majumdar

In an effort to study an alternative approach to make graphene from graphene oxide (GO), exposure of GO to high-energy X-ray radiation has been performed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) have been used to characterize GO before and after irradiation. Results indicate that GO exposed to high-energy radiation is converted to an amorphous carbon phase that is conductive.


2020 ◽  
Author(s):  
Sahar. Mokhtari ◽  
Anthony.W. Wren

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.


2000 ◽  
Vol 15 (10) ◽  
pp. 2076-2079
Author(s):  
Chika Nozaki ◽  
Takashi Yamada ◽  
Kenji Tabata ◽  
Eiji Suzuki

Synthesis of a rutile-type lead-substituted tin oxide with (110) face was investigated. The characterization was performed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, infrared spectroscopy, x-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller surface area measurements. The homogeneous rutile-type lead-substituted tin oxide was obtained until 4.1 mol% of tin was substituted with lead. The surface of obtained oxide had a homogeneously lead-substituted (110) face.


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