scholarly journals One-Pot Synthesis of Ru-Doped ZnO Oxides for Photodegradation of 4-Chlorophenol

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Maria E. Manríquez ◽  
Luis Enrique Noreña ◽  
Jin An Wang ◽  
Lifang Chen ◽  
Jose Salmones ◽  
...  
Keyword(s):  
Band Gap ◽  
Mixed Oxides ◽  
Active Surface ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
One Pot ◽  
Notable Increase ◽  
Doped Zno ◽  
The One

The photocatalytic degradation of 4-chlorophenol in water using Ru-doped ZnO mixed oxides (0, 0.5, 1, and 3 wt% RuO2) synthesized by the one-pot homogeneous coprecipitation method is reported. ZnO with wurtzite structure was present in the mixed oxide as corroborated by Raman spectroscopy and X-ray diffraction analysis. All the samples showed nanorod morphological features. The presence of Ru6+/Ru4+ couples on ZnO modified the band gap of the mixed oxides and led to a shift of the band gap energy from 3.20 eV to 3.07 eV. Ru addition increased the surface area and significantly promoted the formation of active surface oxygen species such as hydroradicals evidenced by the fluorescence spectroscopy measurement. In the photodegradation of 4-chlorophenol solution under UV irradiation, a notable increase in photoactivity was obtained as the amount of RuO2 in the mixed oxides increased to 3 wt%. The charge transfer between Ru6+/Ru4+ couples and ZnO nanoparticles together with the formation of free radical oxidant species effectively inhibits electron-hole recombination rate, thus favoring the photodegradation of 4-chlorophenol.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

The Optical Performance of Holmium Oxide Doped Tellurite Glass for Potential Optical Fiber

2021 ◽  
Vol 317 ◽  
pp. 95-99
Author(s):  
Muhammad Noorazlan Abd Azis ◽  
Halimah Mohamed Kamari ◽  
Suriani Abu Bakar ◽  
Azlina Yahya ◽  
Umar Saad Aliyu
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Gap Energy ◽  
Xrd Method ◽  
Nonlinear Pattern

Borotellurite glass had been widely applied in the field of optical communications and devices. In this work, holmium oxides doped borotellurite glass had been successfully fabricated via conventional melt-quenched technique. The structural properties of holmium doped tellurite glass were found using x-ray diffraction (XRD) method. The nonexistence of sharp peaks in XRD pattern shows that the inclusion of holmium tellurite glass leads to the formation long range of disorderness. The optical properties of the glass system such as refractive index and optical band gap energy are investigated using UV-Vis spectrophotometer. The value of refractive index is found in nonlinear trend along with holmium oxides concentration. It is found that the refractive index is more than 2 at 0.01, 0.03 and 0.04 of holmium concentrations. The optical band gap energy was found in similar trend with refractive index which is in nonlinear pattern.

FeAl2O4 Nanopowders; Structural Analysis and Band Gap Energy

2017 ◽  
Vol 36 (8) ◽  
pp. 789-793 ◽  
Author(s):  
Morteza Enhessari
Keyword(s):  
Structural Analysis ◽  
Band Gap ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Mixed Metal Oxide ◽  
Nanoscale Materials ◽  
X Ray Diffraction ◽  
Organic Precursor ◽  
Gap Energy ◽  
Acid Gel

AbstractNanoscale FeAl2O4 was successfully synthesized via sol–gel method. The sol constituents containing iron and aluminum cations were formed homogenously in stearic acid gel (formation of organic precursor). The pure structural analysis and the size of the spinels were confirmed by X-ray diffraction (XRD). It was observed that the size of the nanoscale materials obtained at around 30–40nm. The micrographs of FeAl2O4 evidenced the homogenous and nanosize formation of spinel. The semiconducting behavior of this mixed metal oxide was observed at 3.14eV based on the band gap energy (Eg). The final nanoscale materials exhibited a superparamagnetic behavior with a saturation magnetization of 9.8 emu/g at applied field of 10 kOe.

Synthesis and Photocatalytic Properties of the Bi2MoO6 and Bi2WO6 Photocatalysts

2018 ◽  
Vol 768 ◽  
pp. 218-223
Author(s):  
Juan Xia ◽  
Lin Zhang ◽  
Qi Wang
Keyword(s):  
Light Absorption ◽  
Hydrothermal Reaction ◽  
Organic Dyes ◽  
High Surface ◽  
Diffuse Reflectance Spectrum ◽  
High Surface Area ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
One Pot

Two different Bi-based semiconductor photocatalysts Bi2MoO6 and Bi2WO6 were synthesized by a simple one-pot hydrothermal reaction at 453 K for 10 h. The properties of the photocatalysts, including structures, morphology, light-absorption band and photoluminescence, etc were characterized by X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectrum and fluorescence spectrum. Further, their photocatalytic properties were compared by the degradation of two different organic dyes: Rhodamine B and methylene blue. It is important to note that the Bi2WO6 nanoplate structure exhibited better photocatalytic activity than the Bi2MoO6 nanowires aggregates due to its high surface area, higher light absorption and lower recombination of electron-hole pairs.

Visible Photoluminescence from SI1-xGEx Quantum Wells

1993 ◽  
Vol 298 ◽  
Author(s):  
T.W. Steiner ◽  
L.C. Lenchyshyn ◽  
M.L.W. Thewalt ◽  
D.C. Houghton ◽  
J.-P. Noël ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Single Photon ◽  
Chemical Vapor ◽  
Band Gap Energy ◽  
Single Photon Detection ◽  
Electron Hole ◽  
Photon Detection ◽  
Time Resolved ◽  
Localized Excitons

AbstractWe have observed photoluminescence from strained SiGe quantum well layers at energies approximately equal to twice the SiGe band-gap energy. This luminescence is caused by the simultaneous recombination of two electron hole pairs yielding a single photon. Detection of luminescence at twice the band-gap has been previously used in Si to observe luminescence originating from electron-hole droplets, biexcitons, bound multiexciton complexes and polyexcitons. Time resolved spectra at twice the band-gap have been obtained from our SiGe samples prepared by molecular beam epitaxy (MIRE) as well as rapid thermal chemical vapor deposition (RTCVD). This new luminescence clearly distinguishes multiexciton or dense e-h plasma processes from single exciton processes such as bound excitons, free excitons or localized excitons, which are difficult to separate in the usual nearinfrared luminescence.

5,6,7,8-Tetrahydronaphthalen-1-amine as Precursor for Thiazolidi­nones and Benzothiazepinones: Synthesis and Atropisomeric Relationship

Synthesis ◽  
2017 ◽  
Vol 49 (23) ◽  
pp. 5167-5175 ◽  
Author(s):  
Bruna Drawanz ◽  
Georgia Zimmer ◽  
Leticia Rodrigues ◽  
Andressa Nörnberg ◽  
Manfredo Hörner ◽  
...  
Keyword(s):  
Small Difference ◽  
Mercaptoacetic Acid ◽  
X Ray Diffraction ◽  
Ring Plane ◽  
One Pot ◽  
X Ray ◽  
Nmr Techniques ◽  
The One ◽  
Electron Donating Groups ◽  
Weak Electron

The one-pot reaction of 5,6,7,8-tetrahydronaphthalen-1-amine, mercaptoacetic acid, and arenealdehydes having strong and weak electron-withdrawing groups gave the corresponding 1,3-thiazolidin-4-ones (47–70%). When arenealdehydes bearing strong and weak electron-donating groups were used as precursors, the 1,4-benzothiazepin-2-ones were obtained (30–72%) by p-TsOH catalysis. All compounds are unknown and were characterized by GC-MS and NMR techniques, and available crystals by X-ray diffraction studies. The atropisomerism phenomenon was observed in several 1,3-thiazolidin-4-ones as confirmed by VTNMR method. The Tc was established as 332 K and the energy required for the interconversion of one atrop­isomer into another is around 16.8 kcal·mol–1. Chemical quantum calculation and NOESY displayed that more stable isomer has the tetrahydro­naphthalene portion below the five-ring plane. Only a small difference between isomers (–0.21 to –0.84 kcal·mol–1) was observed by calculated energy.

scholarly journals Water-Soluble O-, S- and Se-Functionalized Cyclic Acetyl-triaza-phosphines. Synthesis, Characterization and Application in Catalytic Azide-alkyne Cycloaddition

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5479
Author(s):  
Abdallah Mahmoud ◽  
Piotr Smoleński ◽  
M. Guedes da Silva ◽  
Armando Pombeiro
Keyword(s):  
Cycloaddition Reaction ◽  
Structural Features ◽  
Water Soluble ◽  
31P Nmr Spectroscopy ◽  
The Novel ◽  
X Ray Diffraction ◽  
One Pot ◽  
Hirshfeld Surfaces ◽  
The One ◽  
High Yields

The 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane (DAPTA) derivatives, viz. the already reported 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane 5-oxide (DAPTA=O, 1), the novel 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane-5-sulfide (DAPTA=S, 2), and 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane-5-selenide (DAPTA=Se, 3), have been synthesized under mild conditions. They are soluble in water and most common organic solvents and have been characterized using 1H and 31P NMR spectroscopy and, for 2 and 3, also by single crystal X-ray diffraction. The effect of O, S, or Se at the phosphorus atom on the structural features of the compounds has been investigated, also through the analyses of Hirshfeld surfaces. The presence of 1–3 enhances the activity of copper for the catalytic azide-alkyne cycloaddition reaction in an aqueous medium. The combination of cheaply available copper (II) acetate and compound 1 has been used as a catalyst for the one-pot and 1,4-regioselective procedure to obtain 1,2,3-triazoles with high yields and according to ‘click rules’.

Hydrothermal Synthesis and Photocatalytic Activities of BiVO4 with Different Solvent

2013 ◽  
Vol 821-822 ◽  
pp. 80-84
Author(s):  
Bin Li ◽  
Xiao Gang Yang ◽  
Fang Lin Du
Keyword(s):  
Visible Light ◽  
Band Gap ◽  
Photocatalytic Oxidation ◽  
Hydrothermal Reaction ◽  
Raw Materials ◽  
Band Gap Energy ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Water As Solvent ◽  
Photocatalytic Activities

Bismuth-based oxides have attractive photocatalytic properties under visible light. Bismuth vanadate (BiVO4) particles as a visible light-responsive photocatalyst were prepared by a facile hydrothermal reaction method with the different solvent using Bi(NO3)3·5H2O and NH4VO3 as raw materials at 180°C for 18h. The as-prepared samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis absorption spectra (UV-vis). The photocatalytic activity of BiVO4 crystals was evaluated using the photocatalytic oxidation of methylene blue (MB) at room temperature under visible light irradiation. It was found that the morphology and the band gap adsorption edge of BiVO4 are different with the different solvent. The widest band gap energy of BiVO4 obtained with ethylene glycol as solvent is 2.405eV. In addition, the BiVO4 powders exhibit a certain photocatalytic properties to photodegrade MB and the maximum photocatalytic degradation rate is 34% using BiVO4 prepared with water as solvent for 2h.

Properties of CdS Thin Films Grown by Chemical Bath Deposition as a Function of Bath Temperature

2009 ◽  
Vol 609 ◽  
pp. 243-247 ◽  
Author(s):  
H. Moualkia ◽  
S. Hariech ◽  
M.S. Aida
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Bath Temperature ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Cds Thin Films ◽  
Direct Band

The present work deals with the preparation and characterization of cadmium sulfur (CdS) thin films. These films are prepared by chemical bath deposition on the well cleaned glass substrates. The thickness of the samples was measured by using profilometer DEKTAK, structural and optical properties were studied by X-ray diffraction analysis, and UV-visible spectrophotometry. The optical properties of the films have been investigated as a function of temperature. The band gap energy and Urbach energy were also investigated as a function of temperature. From the transmittance data analysis the direct band gap ranges from 2.21 eV to 2.34 eV. A dependence of band gap on temperature has been observed and the possible raisons are discussed. Transmission spectra indicates a high transmission coefficient (75 %). Structural analysis revealed that the films showed cubic structure, and the crystallite size decreased at a higher deposition temperature.

Study on Band Gap Energy of F Doped TiO2 Nanotubes

2017 ◽  
Vol 889 ◽  
pp. 234-238
Author(s):  
Mohd Hasmizam Razali ◽  
Nur Arifah Ismail ◽  
Mahani Yusoff
Keyword(s):  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Small Diameter ◽  
Ultra Violet ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gap Energy ◽  
Transmission Electron ◽  
Xrd Patterns

Pure and F doped TiO2 nanotubes was synthesized using simple hydrothermal method. The hydrothermal was conducted using teflon-liner autoclave and maintained at 150oC for 24 hours. The characterization of synthesised product was carried out using x-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive of x-ray spectroscopy (EDX) and ultra violet – visible light diffuse reflectance spectroscopy (UV-Vis DRS) for band gap measurements. XRD patterns indicated that anatase TiO2 phase was remained after F doping suggested that fluorine was highly dispersed into TiO2 by substituted with O in the TiO2 lattice to formed TiO2-xFx solid solution. Morphology investigation using TEM found out small diameter of nanotubes structure within 8 – 10 nm of pure and F doped TiO2 nanotubes. The band gap energy (Eg) of both nanotubes samples were almost similar proposing that F doping does not modify the band gap energy.

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