scholarly journals N and Fe doped NiO nanoparticles for enhanced photocatalytic degradation of azo dye methylene blue in the presence of visible light

2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Martha Ramesh
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Azo Dye ◽  
Band Edge ◽  
Cubic Phase ◽  
Band Edge Emission ◽  
Face Centered Cubic ◽  
Nio Nanoparticles ◽  
X Ray ◽  
Nio Nps

AbstractPure NiO, N-doped, Fe-doped, N and Fe codoped NiO NPs were fabricated via a precipitation process. The powder X-ray diffraction (XRD) revealed the face centered cubic phase of NiO products. The full width at half maximum (FWHM) of the XRD peak was steadily enlarged with the order of elements N, Fe, N/Fe doped to NiO, and shifted towards a greater angle due to decrease in grain size, as shown by XRD. The average crystallite size of NiO products was calculated, ranging from 6.67 to 3.76 nm, according to the Debye Scherrer formula. The scanning electron microscopy (SEM) demonstrated considerable morphological changes in the produced nanoparticles, including those directed to rock-like geometries (NiO and Fe/NiO nanoparticles) while gas covered-nanocrystals (N/NiO and N/Fe/NiO nanoparticles) were formed using precipitation method. The particle size range of 10–50 nm was estimated using the bar scale in transmission electron microscopy (TEM) pictures. The elemental composition of Ni, O, Fe and N atoms in the respected samples was analyzed by Energy Dispersive X-Ray Analysis (EDX). Photoluminescence (PL) showed band edge emission at 370 nm. The band edge-absorption peak, which is caused by electronic transitions between energy levels, is determined to be in the range 314–325 nm. A UV–Vis analysis found an energy gap amid 3.2 eV and 2.5 eV. The chemical condition of the Fe and N doped NiO composites were validated using XPS. Using visible photo application of undoped and doped NiO NPs, the degradation of an azo dye termed methylene blue was examined. It was N/Fe/NiO (79.8%), Fe/NiO (76%), N/NiO (73%), and NiO (62%) throughout the 6 h irradiation duration. Increased production of OH• radicals was detected in fluorescence tests using terephthalic acid (TA) for N/Fe/NiO NPs, indicating the higher photo-degradation described. Furthermore, the degradation trends of both undoped and doped NiO NPs closely matched the pseudo first order kinetics, according to the kinetic analysis. There was also a suggestion for a thorough MB breakdown mechanism.

scholarly journals Sustainable Synthesis of Silver Nanoparticles Using Marine Algae for Catalytic Degradation of Methylene Blue

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1377
Author(s):  
Chandra Kishore Somasundaram ◽  
Raji Atchudan ◽  
Thomas Nesakumar Jebakumar Immanuel Edison ◽  
Suguna Perumal ◽  
Rajangam Vinodh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Silver Nanoparticles ◽  
Marine Algae ◽  
Dye Degradation ◽  
Catalytic Degradation ◽  
Attenuated Total Reflection ◽  
Face Centered Cubic ◽  
X Ray ◽  
Vis Spectroscopy

Herein, Sargassum coreanum (marine algae)-mediated silver nanoparticles (AgNPs) were successfully synthesized by a simple reduction method. The synthesized AgNPs were characterized using ultraviolet-visible spectroscopy, attenuated total reflection Fourier transformed infrared spectroscopy, X-ray diffractometry, field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray (EDX) spectroscopy, and high-resolution transmission electron microscopy (HR-TEM) analysis. The acquired colloidal AgNPs were strongly absorbed around 420 nm and displayed brown color under visible light. The XRD pattern of AgNPs exposed their face-centered cubic geometry along with crystalline nature. The HRTEM images of synthesized AgNPs confirmed the mean particle size of 19 nm with a distorted spherical shape, and the calculated interlayer distance (d-spacing value) was about 0.24 nm. Further, the catalytic degradation of methylene blue using sodium borohydride and AgNPs was monitored using UV–vis spectroscopy. The result revealed that AgNPs performed as a superior catalyst, which completely degraded MB in 20 min. The rate constant for MB degradation was calculated to be 0.106 min−1, demonstrating that the marine algae-mediated AgNPs had outstanding catalytic activity. This approach is easy and environmentally benign, which can be applied for environmental-based applications such as dye degradation and pollutant detoxification.

scholarly journals Antimicrobial Activity of Silver Nanoparticles Synthesized Using Goat Milk against Pathogens of Selected Vegetables

2019 ◽  
pp. 1-10 ◽  
Author(s):  
T. A. Ihum ◽  
C. C. Iheukwumere ◽  
I. O. Ogbonna ◽  
G. M. Gberikon
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Goat Milk ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

This study was carried out to determine the antimicrobial activity of silver nanoparticles synthesized using goat milk against pathogens of selected vegetables. Synthesis of Silver nanoparticles was done using Goat milk, and characterized using Ultra Violet-Visible absorption spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X- ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Maximum absorbance of Goat milk synthesized AgNPs was observed at 417 nm, with FTIR peaks at 3455 cm−1, 1628 cm−1, 1402 cm−1, 1081 cm−1 and 517 cm−1, indicating that proteins in Goat milk (GM) were the capping and stabilization molecules involved the synthesis of AgNPs. Transmission electron microscopy analysis showed that the biosynthesized particles were spherical in shape having a size of 10-100 nm, X- ray diffraction (XRD) pattern agreed with the crystalline nature and face-centered cubic phase of AgNPs. Evaluation of the antimicrobial activity of AgNPs synthesized using GM against the indicator strains (Staphylococcus aureus CIP 9973, Pectobacterium carotovorum Pec1, Enterobacter cloacae AS10, Klebsiella aerogenes OFM28, Proteus mirabilis UPMSD3 and Escherichia coli 2013C-3342) isolated from selected vegetables, was carried out using the Agar diffusion assay at different concentrations of 25, 75 and 100 µl/ml. The present study demonstrated that the AgNPs synthesized using Goat milk have potent biological activities, which can find applications in diverse areas.

scholarly journals Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Srihasam Saiganesh ◽  
Thyagarajan Krishnan ◽  
Golla Narasimha ◽  
Hesham S. Almoallim ◽  
Sulaiman Ali Alhari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Rare Earth ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nio Nanoparticles ◽  
X Ray ◽  
Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

scholarly journals Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 661
Author(s):  
Zhiwei Ying ◽  
Xinwei Chen ◽  
He Li ◽  
Xinqi Liu ◽  
Chi Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Urban Pollution ◽  
Maximum Adsorption Capacity ◽  
One Pot ◽  
Average Pore ◽  
X Ray ◽  
Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

Stacking Faults in a High Nitrogen Face-Centered-Cubic Phase Formed on Nitrogen-Modified Austenitic Stainless Steel

2008 ◽  
Vol 373-374 ◽  
pp. 318-321
Author(s):  
J. Liang ◽  
M.K. Lei
Keyword(s):  
Stainless Steel ◽  
Plasma Source ◽  
Peak Shift ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
High Nitrogen ◽  
X Ray ◽  
Peak Asymmetry ◽  
Face Centered

Effects of stacking faults in a high nitrogen face-centered-cubic phase (γΝ) formed on plasma source ion nitrided 1Cr18Ni9Ti (18-8 type) austenitic stainless steel on peak shift and peak asymmetry of x-ray diffraction were investigated based on Warren’s theory and Wagner’s method, respectively. The peak shift from peak position of the γΝ phase is ascribed to the deformation faults density α, while the peak asymmetry of the γΝ phase is characterized by deviation of the center of gravity of a peak from the peak maximum (Δ C.G.) due to the twin faults density β. The calculated peak positions of x-ray diffraction patterns are consistent with that measured for plasma source ion nitrided 1Cr18Ni9Ti stainless steel.

scholarly journals Decolorization of Methylene Blue by Ag/SrSnO3 Composites under Ultraviolet Radiation

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Patcharanan Junploy ◽  
Titipun Thongtem ◽  
Somchai Thongtem ◽  
Anukorn Phuruangrat
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Separation Process ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Negative Effect ◽  
Uv Visible

SrSn(OH)6 precursors synthesized by a cyclic microwave radiation (CMR) process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG) were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (EM), Fourier transform infrared (FTIR) spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl) dye under ultraviolet (UV) radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation.

scholarly journals Facile Preparation of Rod-like MnO Nanomixtures via Hydrothermal Approach and Highly Efficient Removal of Methylene Blue for Wastewater Treatment

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Yuelong Xu ◽  
Bin Ren ◽  
Ran Wang ◽  
Lihui Zhang ◽  
Tifeng Jiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Degradation Mechanism ◽  
Dye Adsorption ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Transmission Electron ◽  
Degradation Ratio ◽  
Hydrothermal Approach

In the present study, nanoscale rod-shaped manganese oxide (MnO) mixtures were successfully prepared from graphitic carbon nitride (C3N4) and potassium permanganate (KMnO4) through a hydrothermal method. The as-prepared MnO nanomixtures exhibited high activity in the adsorption and degradation of methylene blue (MB). The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Furthermore, the effects of the dose of MnO nanomixtures, pH of the solution, initial concentration of MB, and the temperature of MB removal in dye adsorption and degradation experiments was investigated. The degradation mechanism of MB upon treatment with MnO nanomixtures and H2O2 was studied and discussed. The results showed that a maximum adsorption capacity of 154 mg g−1 was obtained for a 60 mg L−1 MB solution at pH 9.0 and 25 °C, and the highest MB degradation ratio reached 99.8% under the following optimum conditions: 50 mL of MB solution (20 mg L−1) at room temperature and pH ≈ 8.0 with 7 mg of C, N-doped MnO and 0.5 mL of H2O2.

scholarly journals Green Synthesis and Catalytic Activity of Silver Nanoparticles Based on Piper chaba Stem Extracts

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1777 ◽  
Author(s):  
Md. Mahiuddin ◽  
Prianka Saha ◽  
Bungo Ochiai
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Ftir Spectroscopy ◽  
Visual Observation ◽  
Face Centered Cubic ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Face Centered ◽  
Average Size

A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.

scholarly journals Studies of Effects of Calcination Temperature on the Crystallinity and Optical Properties of Ag-Doped ZnO Nanocomposites

2019 ◽  
Vol 3 (1) ◽  
pp. 18 ◽  
Author(s):  
Md. Molla ◽  
Mai Furukawa ◽  
Ikki Tateishi ◽  
Hideyuki Katsumata ◽  
Satoshi Kaneco
Keyword(s):  
Optical Properties ◽  
Calcination Temperature ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Band Edge ◽  
High Yield ◽  
Band Edge Emission ◽  
X Ray ◽  
Calcination Temperatures ◽  
Doped Zno

Ag-doped ZnO nanocomposites are successfully synthesized at different calcination temperatures and times through a simple, effective, high-yield and low-cost mechanochemical combustion technique. Effects of calcination temperature on the crystallinity and optical properties of Ag/ZnO nanocomposites have been studied by X-ray diffraction (XRD), UV−visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL) and X-ray photoelectron spectroscopy (XPS). The XRD patterns of the synthesized Ag/ZnO exhibit a well-crystalline wurtzite ZnO crystal structure. The grain size of Ag/ZnO nanocomposites is found to be 19 and 46 nm at calcination temperatures of 400 °C and 700 °C, respectively. The maximum absorption in the UV region is obtained for Ag/ZnO nanocomposites synthesized at a calcination temperature of 500 °C for 3 h. The peak position of blue emissions is almost the same for the nanocomposites obtained at 300–700 °C calcination temperatures. The usual band edge emission in the UV is not obtained at 330 nm excitation. Band edge and blue band emissions are observed for the use of low excitation energy at 335–345 nm.

Sol-gel synthesis, characterisation, and photocatalytic activity of porous spinel Co3O4 nanosheets

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Uv Light ◽  
Average Pore Size ◽  
Sol Gel ◽  
Spherical Particles ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Oriented Growth

AbstractMesoporous spinel Co3O4 nanosheets were synthesised via a simple sol-gel route using the Pluronic P123 triblock copolymer as the stabilising agent. Their structural, morphological, and textural properties were characterised. FTIR spectrum revealed the formation of cobalt oxide without any surface adsorbed impurities. Face centered cubic phase of spinel Co3O4 with the mean crystalline size of 26 nm was assigned by the X-ray diffraction analysis without the formation of other phases. Porous nanosheets and cave-like morphologies were identified from the scanning electron microscopy (SEM) images. Highly agglomerated more or less spherical particles with well separated lattice fringes, representing the oriented growth of nanocrystals, were noticed on the transmission electron microscopy photographs. Surface area analysis revealed that the spinel has high surface area of about 25 m2 g−1 with monomodal mesoporosity. The average pore size distribution was found to be about 15.8 nm. The as-prepared spinel photocatalyst showed a mild photocatalytic activity in the degradation of methylene blue (2.5 mg L−1) under UV light irradiation with air as the oxidising agent. Photocatalytic activity of the as-prepared reusable Co3O4 was found to be higher than that of the commercial spinel powder.

Sign in / Sign up

Export Citation Format

Share Document