scholarly journals Solar photodegradation of a textile azo dye using synthesized ZnO/Bentonite

2016 ◽  
Vol 75 (5) ◽  
pp. 1211-1220 ◽  
Author(s):  
B. Boutra ◽  
M. Trari
Keyword(s):  
Azo Dye ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Impregnation Method ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Optical Gap ◽  
Optimal Ph

The present work is devoted to the synthesis of a new photocatalyst ZnO (7.5%)/Bentonite prepared by impregnation method and its successful application for the degradation of Solophenyl Red 3BL (SR 3BL) under solar light (∼660 W/m2). The X-ray diffraction (XRD) indicates mixed phases of the nanocomposite catalyst (ZnO/Bentonite), characterized by scanning electron microscopy, X-ray fluorescence and attenuated total reflection. The optical properties confirm the presence of the Wurtzite ZnO phase with an optical gap of 3.27 eV. The catalyst dose (0.25–1 gL−1), pH solution (2.5–11) and initial dye concentration (5–75 mg/L) are optimized. The optimal pH (∼6.7) is close to the natural environment. The photodegradation yield increases with decreasing the SR 3BL concentration. The equilibrium is reached within 160 min and the data are well fitted by the Langmuir-Hinshelwood model; the SR 3BL disappearance obeys to a first-order kinetic with an apparent rate constant of 10−2 mn−1. The best yield of SR 3BL photodegradation (92%) is achieved for a concentration of 5 mg/L and a catalyst dose of 0.75 gL−1 at free pH.

Physicochemical Characteristics of an Ultra-Thin Hydrophobic Trichlorosilanes Using SiO2 as Adhesion

2019 ◽  
Vol 796 ◽  
pp. 80-87
Author(s):  
Akinsanya Damilare Baruwa ◽  
Esther Titilayo Akinlabi ◽  
Oluseyi Philip Oladijo ◽  
Stephen Akinwale Akinlabi ◽  
Jeff Chinn
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Physicochemical Characteristics ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Natural Seawater ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrophobic Silane ◽  
Better Than

The aim of the research is to subject the three different silanes to chemical and electrochemical investigations in other to determine the most efficient organic compound. Three types of hydrophobic silanes [Tris (Trimethylsiloxy) silyethyl] dimethylchlorosilane (Alkyl); Tridecafloro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) and Henicosyl-1,1,2,2-tetrahydrododecyltricholrosilane (FDDTS) are presented and investigated. The three silanes are of different composition but are deposited at the same parameters and conditions. The chemical investigation was studied through (attenuated total reflection Fourier-transform infrared (ATR-FTIR) and x-ray diffraction (XRD), while the electrochemical study was conducted through EIS using natural seawater electrolyte at room temperature. From the investigation techniques, only electrochemical impedance results show that FDDTS performed better than both Alkyl and FOTS. The chemical analysis showed the presence of hydrophobic silane on all the coated samples, and no distinction can be drawn from associated peaks.

scholarly journals Synthesis and characterization of four new halloysite–TiO2 nanocomposites.

2013 ◽  
Vol 47 (1) ◽  
pp. 407
Author(s):  
D. Papoulis ◽  
S. Komarneni ◽  
D. Toli ◽  
D. Panagiotaras ◽  
S. Bakalis
Keyword(s):  
Sol Gel ◽  
Particle Morphology ◽  
Anatase Tio2 ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Published Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tio2 Particles

The synthesis as well as the characterization of small-sized TiO2 particles supported on Halloysite are presented. Hallloysite from Utah, USA as well as from Limnos, island Greece, were used to synthesize two nanocomposites for each halloysite with TiO2 to halloysite weight ratios of 80: 20 and 60:40 and compare with published data of well formed nanocomposites of intermediate proportion (70-30) that were previously studied. All nanocomposites were prepared by deposition of anatase (TiO2) on the halloysite tubes using a sol–gel method under hydrothermal treatment at 180 °C. Phase composition, particle morphology and physical properties of these samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Attenuated Total Reflection using Fourier Transform Infrared spectroscopy (ATR-FTIR) and N2 surface area analysis by BET. Preparation of all halloysite–TiO2 nanocomposites led to the anticipated good dispersion of anatase particles on halloysite surfaces. ATR-FTIR results revealed the formation of hydrogen bonding between anatase and the outer surfaces of halloysite tubes. All halloysite-TiO2 nanocomposites largely showed interparticle mesopores of about 5.7nm and high SSAs.

scholarly journals Pengamatan Surface Plasmon Resonance pada ZnO Nanorods dengan Menggunakan Konfigurasi Prisma/Au/ZnO

2020 ◽  
Vol 23 (1) ◽  
pp. 27
Author(s):  
Rina Dewi Mayasari ◽  
Ajeng Novita Sari ◽  
Aditya Eka Mulyono ◽  
Agus Setyo Budi ◽  
Ratno Nuryadi
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Zno Nanorods ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
X Ray ◽  
20 Nm ◽  
Scanning Electron

Pengamatan fenomena surface plasmon resonance (SPR) telah berhasil dilakukan pada ZnO nanorods yang ditumbuhkan di atas lapisan tipis emas. Sistem SPR menggunakan konfigurasi Kretschmann termodifikasi dimana permukaan prisma dideposisi dengan lapisan tipis emas dan ZnO nanorods (prisma/Au/ZnO). Penumbuhan ZnO nanorods menggunakan metode hidrotermal dengan dua tahapan, yaitu pelapisan ZnO seed dan penumbuhan rods. Waktu penumbuhan divariasikan selama 5 menit, 2 jam, dan 4 jam, pada suhu 95 °C yang diikuti dengan annealing pada suhu 500 °C selama 1 jam. Struktur ZnO dikarakterisasi dengan X-ray diffraction (XRD), field emission scanning electron microscope - energy dispersive X-ray spectroscopy (FESEM-EDS), serta diamati fenomena SPR melalui grafik attenuated total reflection (ATR). Hasil karakterisasi menunjukkan bahwa ZnO nanorods (2 jam dan 4 jam) memiliki struktur kristal heksagonal dengan distribusi ukuran diameter pada rentang 20 nm – 60 nm. Fenomena SPR hanya teramati pada nanopartikel ZnO (5 menit) pada sudut SPR (θSPR) 58,2°. Fenomena SPR tidak terlihat pada ZnO nanorods (2 jam dan 4 jam) dikarenakan panjang rods melebihi 100 nm.

Core-shell Mn3O4/birnessite-MnO2 hierachical structure with enhanced adsorption towards methylene blue

2016 ◽  
Vol 09 (02) ◽  
pp. 1650020 ◽  
Author(s):  
Feifan Huang ◽  
Bowen Zhou ◽  
Han Xiao ◽  
Wei Xiao
Keyword(s):  
Methylene Blue ◽  
Manganese Oxides ◽  
Core Shell ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
The Individual

The core-shell Mn3O4/birnessite-MnO2 (Mn3O4/MnO2) was successfully established by assembly of birnessite-type MnO2 over Mn3O4 backbones. The product was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), as well as UV–vis absorption spectra (UV–vis) to assess its adsorption of methylene blue (MB) from neutral aqueous solutions. Compared to the individual Mn3O4, the prepared Mn3O4/MnO2 shows enhanced adsorption capability towards MB. Such enhancement is due to the higher surface area and the unique nanosheet shells. The adsorption of MB on the surface of Mn3O4/MnO2 was studied in terms of pseudo-first-order and the pseudo-second-order kinetic models, and the latter was found better. The present study indicates that hierarchically structured core-shell manganese oxides are promising adsorbents for wastewater treatment.

Direct Synthesis of Pure Radiative Vo2 (M) Plate Like Structures Via Hydrothermolysis at Low Temperature

2012 ◽  
Vol 1406 ◽  
Author(s):  
A. Simo ◽  
L.C. Edomwonyi-Otu ◽  
R. Madjoe ◽  
M. Maaza
Keyword(s):  
Direct Synthesis ◽  
High Surface ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Vibrational Bands ◽  
High Surface Energy ◽  
Scanning Electron

ABSTRACTFacile and direct synthesis of radiative VO2 (M) plate-like is reported. The snowflake material presents superstructures plate-like aggregate with an anisotropic orientation in shape governed by V2O5 and NaOH concentration giving high surface energy liable for chemical reactions with the medium. Pure crystalline VO2 (M) has been obtained with a complete hydrothermolysis of the precursor. The morphological, structural, elemental composition, crystallinity and vibrational bands of the powders were characterized by Powder X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Selected Area Electron Diffraction (SAED) and Fourier Transform-Attenuated Total Reflection (FTIR-ATR) infrared spectroscopy.

scholarly journals Efficient Molybdenum Hydrazonato Epoxidation Catalysts Operating under Green Chemistry Conditions: Water vs. Decane Competition

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 756
Author(s):  
Silvija Mrkonja ◽  
Edi Topić ◽  
Mirna Mandarić ◽  
Dominique Agustin ◽  
Jana Pisk
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Theoretical Calculations ◽  
Catalyst Activity ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tert Butylhydroperoxide ◽  
Solid State Structures

Molybdenum compounds containing benzaldehyde-based hydrazones were obtained. The reaction in MeOH resulted with monomeric Mo complexes, [MoO2(L)(MeOH)], while the reaction in dichloromethane (DCM) provided oligomeric complexes, [MoO2(L)]n. The solid-state structures of the obtained compounds were investigated through Infrared Spectroscopy - Attenuated Total Reflection (IR-ATR), Thermogravimetric analysis (TGA), and via X-ray diffraction. The prepared molybdenum species were employed as cyclooctene epoxidation catalysts. TBHP (tert-butylhydroperoxide) in water and TBHP in decane were employed and compared as oxidants, with 0.25 mol% [Mo]. The catalyst activity and selectivity towards epoxide is >90% for all the reactions. The results have been linked to theoretical calculations, showing the importance of the first step, i.e., the transformation of [MoO2(L)(MeOH)] into the pentacoordinate [MoO2(L)].

scholarly journals Enhanced photocatalytic degradation of doxycycline using a magnetic polymer-ZnO composite

2018 ◽  
Vol 2017 (3) ◽  
pp. 791-801 ◽  
Author(s):  
Ali Mohammadi ◽  
Shabnam Pourmoslemi
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Degradation ◽  
Extraction Efficiency ◽  
Nano Particles ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Polymer Precipitation ◽  
Order Kinetic Model

Abstract A novel magnetic polymer-ZnO composite was prepared by incorporating Fe3O4 and ZnO nano-particles in the structure of an adsorbent polymer. Precipitation polymerization was used for synthesizing the adsorbent polymer and its efficiency for extracting doxycycline from aqueous solution was optimized according to several parameters including time, pH and amount of polymer. Results showed the highest extraction efficiency at neutral pH of the doxycycline solution in 20 min, and the capacity of the polymer was about 20 mg/g. The magnetic property of a material is important for fast and facile separation of composite particles after each use. Magnetic polymer-ZnO composite was synthesized by adding Fe3O4 and ZnO nano-particles to the polymerization mixture in order to take advantage of both sorption and photocatalytic degradation mechanisms. The obtained composite was characterized using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy equipped with wavelength dispersive X-ray spectroscopy and used for enhanced photocatalytic degradation of doxycycline in aqueous solution. Results showed 76.5% degradation of doxycycline in 6 hours which was significantly higher than the degradation observed by an equivalent amount of ZnO nano-particles. Photocatalytic degradation of doxycycline fitted the pseudo first order kinetic model with a rate constant of 4 × 10−3 μg mL−1 min−1.

Preparation of n-type polyaniline/hexagonal boron nitride composites with a large thermoelectric power factor

2021 ◽  
pp. 096739112110425
Author(s):  
Volkan Ugraskan ◽  
Ebubekir Ceran ◽  
Ozlem Yazici
Keyword(s):  
Boron Nitride ◽  
Power Factor ◽  
Hexagonal Boron Nitride ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
Thermoelectric Power Factor ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Vis Spectroscopy

In the present study, it was aimed to investigate the thermoelectric (TE) properties of polyaniline/hexagonal boron nitride (PANI/h-BN) composites. First, h-BN was synthesized from boric acid and urea. Then, PANI-HCl was synthesized by oxidative chemical polymerization. Finally, the composites were prepared using different weight ratios of h-BN. The composites were characterized using attenuated total reflection accessory attached Fourier-transform infrared spectroscopy, UV-vis spectroscopy, X-ray diffraction, and scanning electron microscopy/energy dispersive X-ray analyzer. TE investigation of the composites showed that the addition of h-BN significantly contributes to the TE properties of PANI-HCl. The addition of h-BN increased the power factor of PANI-HCl from 0.07 μWm−1K−2 to 143.05 μWm−1K−2. Furthermore, all the composites showed negative Seebeck coefficients which are the characteristics of n-type semiconductors.

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