scholarly journals Selective Oxidation of Styrene to Benzaldehyde by Co-Ag Codoped ZnO Catalyst and H2O2 as Oxidant

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Abderrazak Aberkouks ◽  
Ayoub Abdelkader Mekkaoui ◽  
Brahim Boualy ◽  
Soufiane El Houssame ◽  
Mustapha Ait Ali ◽  
...  
Keyword(s):  
Reaction Time ◽  
Catalytic Oxidation ◽  
Selective Oxidation ◽  
High Selectivity ◽  
Sol Gel ◽  
Good Activity ◽  
Molar Ratios ◽  
Selective Catalytic Oxidation ◽  
Sol Gel Process ◽  
Ft Ir

Various ratio of Co-Ag supported on ZnO have been evaluated in the selective catalytic oxidation of styrene to benzaldehyde, using H2O2 as an oxidant. The catalysts were prepared by a sol-gel process and were characterized using XRD, FT-IR, TG-DTG, BET, and SEM/EDX. The performance of the prepared catalyst was investigated under different parameters such as solvent, temperature, substrate/oxidant molar ratios, reaction time, and doping percent. The Zn1−x−yAgxCoyO catalysts exhibit a good activity and a high selectivity towards benzaldehyde (95%) with the formation of only 5% of acetophenone.

scholarly journals New Hybrid Materials Synthesized with Different Dyes by Sol-Gel Method

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ramona Gheonea ◽  
Eleonora Cornelia Crasmareanu ◽  
Nicoleta Plesu ◽  
Sorin Sauca ◽  
Vasile Simulescu ◽  
...  
Keyword(s):  
Organic Dyes ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Molar Ratios ◽  
Vis Spectroscopy ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Molecular Manipulation ◽  
Low Temperature Process

One well-known method for hybrids synthesis with incorporated organic dyes is sol-gel method, which is based on the concept of molecular manipulation to design ceramics, glasses, and composites. The low-temperature process allows for the incorporation of guest organic molecules within the inorganic matrix, as well as for the synthesis of hybrid networks in which the organic and inorganic phases are interpenetrating. The aim of the work presented in this paper was the preparation of the gels with three different dyes, at different molar ratios by using the hydrolytic sol-gel process. The interaction of the dye and the oxide was examined by UV-vis spectroscopy and FT-IR. The thermal stability of the hybrid organic-inorganic xerogel formed here was studied by thermal analysis. The micrographs obtained by scanning electron microscopy (SEM) revealed the high density of the films. Such characteristics indicate the possible application of these films in solar cells.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Synthesis of a Ruthenium Complex Based on 2,6-Bis[1-(Pyridin-2-yl)-1H-Benzo[d]Imidazol-2-yl]Pyridine and Catalytic Oxidation of (1H-Benzo[d]-Imidazol-2-yl)Methanol to 1H-Benzo[d]Imidazole-2-Carbaldehyde with H2O2

2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni
Keyword(s):  
Reaction Time ◽  
Catalytic Oxidation ◽  
Reaction Temperature ◽  
Ruthenium Complex ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Optimal Reaction

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.

scholarly journals Synthesis of ZnO and CuO nanoparticles via Sol gel method and Its Characterization by using XRD and FT-IR Analysis

2022 ◽  
Author(s):  
Monika Patel ◽  
Sunita Mishra ◽  
Ruchi Verma ◽  
Deep Shikha
Keyword(s):  
Particle Size ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Broad Band ◽  
Zinc Nitrate ◽  
Zno Nanoparticle ◽  
Absorption Bands ◽  
Characteristic Absorption ◽  
Sol Gel Process ◽  
Ft Ir

Abstract Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1-100 nm) with various crystal shapes which include spherical nanoparticles, flower shaped, Nano rods, Nano ribbons, and Nano platelets. Metals have ability to produce large number of oxides. These metal oxides play an major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol-gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.24760 was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm-1 can be attributed to the characteristic absorption of O-H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19cm−1 which refer to the formation of CuO. A broad absorption peak noticed at 3308.2 cm−1 attributed to O–H stretching of the moisture content.

Hybrid Nanocomposites Based on Metal Oxides and Polysiloxanes with Controlled Morphology

2007 ◽  
Vol 1007 ◽  
Author(s):  
Sorin Ivanovici ◽  
Christoph Rill ◽  
Claudia Feldgitscher ◽  
Guido Kickelbick
Keyword(s):  
Metal Oxides ◽  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanoparticles ◽  
Spectroscopic Methods ◽  
Metal Alkoxides ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Controlled Morphology

ABSTRACTHybrid materials based on polysiloxanes and metal oxides (SiO2, TiO2, ZrO2) were prepared by hydrosilation of allyl acetoacetate (AAA) modified metal alkoxides (M(OR)4; M = Ti, Zr; R = ethyl, isopropyl) or vinyl triethoxysilane with poly(dimethylsiloxane-co-hydrosiloxane) (PDMS-co-PMHS). The obtained compounds acted as single-source precursors in the sol-gel process. Various spectroscopic methods showed the complete functionalization of the polysiloxane chains with the complexes. When alcohols were used as solvents in the sol-gel process, hybrid nanoparticles were obtained, as observed by dynamic light scattering (DLS) measurements, transmission electron microscopy (TEM), and spectroscopic methods such as NMR and FT-IR.

Catalytic Application of H4SiW12O40/SiO2 in Synthesis of Acetals and Ketals

2011 ◽  
Vol 284-286 ◽  
pp. 2374-2379 ◽  
Author(s):  
Shui Jin Yang ◽  
Yong Kui Huang ◽  
Li Yu
Keyword(s):  
Reaction Time ◽  
High Activity ◽  
Sol Gel ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
Catalytic Application ◽  
Ft Ir ◽  
Gel Technique ◽  
Catalyst Dosage ◽  
Novel Catalyst

A novel catalyst, H4SiW12O40/SiO2was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of H4SiW12O40/SiO2for synthesis of acetals and ketals were tested. The variation of different reaction parameters, such as mole ratio of aldehyde/ketone to alcohols, catalyst dosage and reaction time on the yield of acetals and ketals were also studied. The results reveal that the H4SiW12O40/SiO2catalysis generally results in good yields of acetals and ketals under mild reaction conditions and the high activity and stability of the catalyst is well retained on recycling.

Influence of Li2+ Doping on the Structural and Optical Properties of CaO Synthesized by Sol–Gel Process

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Lithium Nitrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sol Gel Process ◽  
Ft Ir ◽  
First Time

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.

Synthesis of V2O5 Powders by EDTA Assistance Ultrasound Sol-Gel Process

2012 ◽  
Vol 512-515 ◽  
pp. 207-210
Author(s):  
Quan Wen ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Activation Energy ◽  
Raw Materials ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Calcination Temperatures ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Precursor Powders ◽  
Influence Of Ph

V2O5 powders were successfully synthesized by the EDTA assistanced ultrasound sol-gel process using NH4VO3 and EDTA, NH3•H2O as raw materials. The synthesized activation energy and the influence of pH values and the calcination temperatures on the phases and microstructures of powders were particularly investigated. The precursor powders and the V2O5 powders were characterized by X-ray diffraction (XRD), fourier transform inelectron microscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry-thermal gravimetric (DSC-TG). Results show that the obtained products exhibit good crystallization under the conditions of pH=4, calcination temperature 400~500 °C and calcination time 0.5 h during the synthesizing process. The as-prepared V2O5 powders show preferred growth orientation along (001) plane at the pH=4. By DSC analysis, the ultrasonic cavitation result in the decrease in synthesized activation energy obviously than that was prepared without ultrasonic irradiation.

Effect of TiO2 Nanoparticles on the Hydrophilicity of Sulfonated-Polyethersulfone

2009 ◽  
Vol 79-82 ◽  
pp. 663-666 ◽  
Author(s):  
Ming Liang Luo ◽  
Qing Zhi Wen ◽  
Hong Jian Liu ◽  
Jia Lin Liu
Keyword(s):  
Sol Gel ◽  
Coordination Bond ◽  
Tio2 Nanoparticle ◽  
Interaction Theory ◽  
Tio2 Content ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Nanoparticle Composites ◽  
Sulfonated Polyethersulfone ◽  
Nanosized Tio2

Sulfonated-polyethersulfone/TiO2 (SPES/TiO2) nanoparticle composites with different TiO2 content were prepared by a sol-gel process. These composites have nanosized TiO2 rich domains well dispersed within SPES matrix observed by SEM photograph. The effect of TiO2 nanoparticles on the hydrophilicity of SPES was discussed by contact angle goniometer. The mechanism of the hydrophilicity improvement of these composites was analyzed by the molecular interaction theory and FT-IR. The hydrogen bond and coordination bond between SPES and TiO2 nanoparticle were observed. Comparing with the pure SPES, the SPES/TiO2 composites exhibited an outstanding increase in hydrophilicity.

Microstructural characteristics and photoluminescence performance of nanograined thermally treated CeO2-TiO2 xerogels

2007 ◽  
Vol 22 (5) ◽  
pp. 1182-1187
Author(s):  
Amita Verma ◽  
A.K. Srivastava ◽  
N. Karar ◽  
Harish Chander ◽  
S.A. Agnihotry
Keyword(s):  
Electron Microscopy ◽  
Crystallite Size ◽  
Sol Gel ◽  
Structural Features ◽  
X Ray Diffraction ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Crystallite Sizes ◽  
Thermally Treated

Nanostructured thermally treated xerogels have been synthesized using a sol-gel process involving cerium (Ce) chloride heptahydrate and titanium (Ti) propoxide mixed in different Ce:Ti molar ratios. Structural features of the xerogels have been correlated with their photoluminescence (PL) response. The crystallite sizes in the samples lie in the nanorange. The x-ray diffraction and transmission electron microscopy results have confirmed the coexistence of CeO2 and TiO2 nanocrystallites in these xerogels. In general, a decrease in the CeO2 crystallite size and an increase in the TiO2 crystallite size are observed in the xerogels as a function of Ti content. Scanning electron microscopy results have evidenced the evolution of ordered structure in the xerogels as a function of TiO2 content. Although both of the phases (CeO2 and TiO2) have exhibited PL in ultraviolet and visible regions, the major luminescence contribution has been made by the CeO2 phase. The largest sized CeO2 crystallites in 1:1 thermally treated xerogel have led to its highest PL response. PL emission in the xerogels is assigned to their nanocrystalline nature and oxygen vacancy-related defects.

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