scholarly journals Enhancement of both optical and catalytic activity of copper-decorated porous silicon micro-particles

2021 ◽  
Vol 93 (3) ◽  
pp. 30402
Author(s):  
Abderrahmane Hamdi ◽  
Chohdi Amri ◽  
Rachid Ouertani ◽  
Elhadj Dogheche ◽  
Hatem Ezzaouia
Keyword(s):  
Catalytic Activity ◽  
Chemical Vapour ◽  
Catalytic Performance ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Micro Particles ◽  
Good Crystallinity ◽  
Short Times

To the best of our knowledge, this study is the first to investigate the effect of chemical vapour etching (CVE) combined with copper decoration on both the optical and catalytic activities of silicon micro-particles (SiμPs). After exposure to acid vapours emanating from a hot solution of hydrogen fluoride/nitric acid (HF/HNO3), scanning electron microscope images of the treated powder show the formation of a porous, sponge-like structure on the sidewalls of SiμPs. Fourier transmission infra-red analysis shows the appearance of hydride bonds related to the formation of the porous structure. X-ray diffraction measurements and Raman spectroscopy show the good crystallinity of the samples. The strong photoluminescence properties of the obtained porous SiμPs (pSiμPs) reveal that the vapour etching process generated silicon nanocrystals within these particles. In this work, we have investigated the catalytic activity of copper nanoparticles (CuNPs) loaded on the surface of pSiμPs, in order to reduce the toxic compound 4-nitrophenol to 4-aminophenol. The results show excellent catalytic performance in very short times (less than 1 min).

Synthesis and Photoluminescence Properties of Novel SnO2 Zigzag Nanoribbons

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ceramic Boat

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.

scholarly journals Synthesis of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

scholarly journals Catalytic Performance of TiO2–Carbon Mesoporous-Derived from Fish Bones in Styrene Oxidation with Aqueous Hydrogen Peroxide as an Oxidant

2021 ◽  
Vol 16 (1) ◽  
pp. 88-96
Author(s):  
Mukhamad Nurhadi ◽  
Ratna Kusumawardani ◽  
Teguh Wirawan ◽  
Sumari Sumari ◽  
Sin Yuan Lai ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Styrene Oxidation ◽  
Aqueous Hydrogen Peroxide ◽  
X Ray ◽  
Fish Bones ◽  
Adsorption Desorption ◽  
Kinetics Of

The catalytic performance of titania-supported carbon mesoporous-derived from fish bones (TiO2/CFB) has been investigated in styrene oxidation with aqueous H2O2. The preparation steps of (TiO2/CFB) catalyst involved the carbonization of fish bones powder at 500 °C for 2 h. followed by impregnation of titania using titanium(IV) isopropoxide (500 µmol) precursor, and calcined at 350 °C for 3 h. The physical properties of the adsorbents were characterized using Fourier transform infrared, X-ray diffraction (XRD), Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), and nitrogen adsorption-desorption studies. The catalytic test was carried out using styrene oxidation with H2O2 as an oxidant at room temperature for 24 h. Its catalytic activity was compared with Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts. It is demonstrated that the catalytic activity of TiO2/CFB catalyst has the highest compared to Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts in the oxidation of styrene with styrene conversion ~23% and benzaldehyde selectivity ~90%. Kinetics of TiO2/CFB catalyzed oxidation of styrene has been investigated and mechanism for oxidation of styrene has been proposed. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals Crystal Structure and Catalytic Activity of Poly[bis(3-bromo-2-hydroxybenzaldehyde)-2-aminopyrimidinemagnesium(II)] for Hydrogenation of 1,3-Butadiene

2021 ◽  
Vol 16 (2) ◽  
pp. 260-266
Author(s):  
Li-Hua Wang ◽  
Fan-Yuan Kong ◽  
Xi-Shi Tai
Keyword(s):  
Catalytic Activity ◽  
Coordination Polymer ◽  
X Ray Diffraction ◽  
Acetate Dihydrate ◽  
X Ray ◽  
Catalytic Activities ◽  
Distorted Octahedral Coordination Geometry ◽  
Distorted Octahedral ◽  
Good Catalytic Activity ◽  
Open Access Article

A new six-coordinated Mn(II) coordination polymer, [Mn(L1)(L2)2]n (L1 = 2-aminopyrimidine, HL2 = 3-bromo-2-hydroxybenzaldehyde) was synthesized by 3-bromo-2-hydroxybenzaldehyde, NaOH, 2-aminopyrimidine and manganese(II) acetate dihydrate. The Mn(II) coordination polymer was structural characterized by elemental analysis and single crystal X-ray diffraction. The results show that each Mn(II) ion is six-coordinated with two phenolic hydroxyl O atoms from two 3-bromo-2-hydroxybenzaldehyde ligands (O1 and O4), two formyl group O atoms from two 3-bromo-2-hydroxybenzaldehyde ligands (O2 and O3), and two N atoms from two 2-aminopyrimidine molecules (N1A and N2), and forms a distorted octahedral coordination geometry. The Mn(II) coordination polymer displays a 1D chained structure by the bridge effect of 2-aminopyrimidine N atoms. The catalytic activities of Mn(II) coordination polymer and Pd@Mn(II) coordination polymer for hydrogenation of 1,3-butadiene have been investigated. The Pd@Mn(II) coordination polymer catalyst shows the good catalytic activity and selectivity in  the hydrogenation of 1,3-butadiene. The 1,3-butadiene conversion is 61.3% at 70 °C, and the selectivity to total butene is close to 100%. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Catalytic Activity of Ba Doped Ta2O5 for Methylene Blue Degradation under Visible Light

2010 ◽  
Vol 156-157 ◽  
pp. 1440-1443
Author(s):  
Yan Hong Zhao ◽  
Min Sun ◽  
Shu Wei Wang ◽  
Wen Ming Tong ◽  
Xiao Jing Wang
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Visible Light ◽  
Tantalum Oxide ◽  
X Ray Diffraction ◽  
Methylene Blue Degradation ◽  
X Ray ◽  
First Order ◽  
Good Crystallinity ◽  
Kinetics Of

The Ba doped tantalum oxide (Ba-Ta2O5) particles were synthesized using low temperature hydrothermal method. The phase structure of samples was characterized by X-ray diffraction (XRD). The result showed that Ba-Ta2O5 had still good crystallinity and belonged to rhombic crystal. The catalytic activity of samples was investigated with the degradation methylene blue (MB) under visible light. The degradation efficiency attained 82% when the reaction time was 12 h. The kinetics of MB degradation was respect to the first-order.

Assembling of 12-Tungstophosphoric Acid into Amino-Modified SBA-15 and its Catalytic Performance

2012 ◽  
Vol 465 ◽  
pp. 224-228 ◽  
Author(s):  
Hong Qi Guo ◽  
Gong Yan ◽  
Ming Qing Chen ◽  
Shi Rong Liu
Keyword(s):  
Catalytic Performance ◽  
Tungstophosphoric Acid ◽  
Esterification Reaction ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Ft Ir ◽  
Adsorption Desorption ◽  
Ft Ir Spectroscopy

12-tungstophosphoric acid was supported on amine-modified SBA-15 by impregnation. The structure and properties of the catalyst were characterized by FT-IR spectroscopy, X-ray diffraction, N2 adsorption-desorption, TEM,Raman spectra and NH3–TPD technology.the result confirmed the mesostructure for SBA-15 and the Keggin structure of the heteropolyanions was preserved. The tungstophosphoric acid can disperse in the pore of the support SBA-15/NH2, but the acidity of the catalyst reduced. The catalytic activities of the catalysts were evaluated for the esterification reaction of ethyl acetoacetate and ethylene glycol .and the catalysts supported on amine-modified SBA-15 show excellent reusability and selectivity.

scholarly journals Fe(III) Complexes in Cyclohexane Oxidation: Comparison of Catalytic Activities under Different Energy Stimuli

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1175
Author(s):  
Tannistha Roy Barman ◽  
Manas Sutradhar ◽  
Elisabete C. B. A. Alegria ◽  
Maria de Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Catalytic Activity ◽  
Product Yield ◽  
Conventional Heating ◽  
Ionization Mass ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Total Product ◽  
Physicochemical Methods ◽  
Catalytic Performances

In this study, the mononuclear Fe(III) complex [Fe(HL)(NO3)(H2O)2]NO3 (1) derived from Nʹ-acetylpyrazine-2-carbohydrazide (H2L) was synthesized and characterized by several physicochemical methods, e.g., elemental analysis, infrared (IR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and single crystal X-ray diffraction analysis. The catalytic performances of 1 and the previously reported complexes [Fe(HL)Cl2] (2) and [Fe(HL)Cl(μ-OMe)]2 (3) towards the peroxidative oxidation of cyclohexane under three different energy stimuli (microwave irradiation, ultrasound, and conventional heating) were compared. 1-3 displayed homogeneous catalytic activity, leading to the formation of cyclohexanol and cyclohexanone as final products, with a high selectivity for the alcohol (up to 95%). Complex 1 exhibited the highest catalytic activity, with a total product yield of 38% (cyclohexanol + cyclohexanone) under optimized microwave-assisted conditions.

Use of Carbon Nanomaterials as a Catalyst Support in Fuel Cells

2016 ◽  
Vol 879 ◽  
pp. 1882-1888
Author(s):  
Yoshiyuki Suda
Keyword(s):  
Catalytic Activity ◽  
Carbon Nanomaterials ◽  
Reduction Method ◽  
Catalyst Support ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Ptru Catalyst ◽  
Different Shapes

PtRu or Pt catalysts were supported on four types of carbon nanomaterials with different shapes, sizes, and graphitic and electrical properties, and their resulting catalytic activities were evaluated by electrochemical methods. The carbon nanomaterials used included two types of particles: Arc Black (AcB) and Vulcan XC-72R (Vulcan), and two types of nanofibers: carbon nanocoils (CNC) and VGCF-X. Pt and Ru were loaded onto the nanomaterials by a reduction method using sodium borohydride. Transmission electron microscopy and X-ray diffraction (XRD) revealed the PtRu catalyst particles to be 4–6 nm in diameters. The shifts in the Pt (111) XRD peaks of the catalysts on CNC and VGCF-X were larger than those on AcB and Vulcan, indicating a higher degree of alloying between Pt and Ru. The diameters of the CNC-supported Pt and PtRu catalyst particles had the narrowest distributions and were constant within the range of catalyst loadings investigated. Electrochemical studies of the catalysts during methanol oxidation were carried out using cyclic voltammetry. The catalyst particles supported on CNC and VGCF-X exhibited higher catalytic activity than those on AcB and Vulcan. The effect of the surface area of the carbon nanomaterials on the catalytic activity is discussed.

scholarly journals Natural Clay of Pasaman Barat Enriched by CaO of Chicken Eggshells as Catalyst for Biodiesel Production

2020 ◽  
Vol 15 (3) ◽  
pp. 662-673
Author(s):  
Syukri Syukri ◽  
Kevin Septioga ◽  
Syukri Arief ◽  
Yulia Eka Putri ◽  
Mai Efdi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Broiler Chicken ◽  
Catalytic Performance ◽  
Biodiesel Production ◽  
Main Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Activity Test ◽  
West Sumatra ◽  
The Fourier Transform

This study uses broiler chicken eggshells to enhance catalytic activity of clay obtained from Pasaman Barat (West Sumatra, Indonesia) in lab-scale biodiesel production. The eggshell is a source of calcium oxide (CaO) which operates as a catalyst when mixed with the clay (Ca-Clay). Two other catalysts were also prepared as comparisons by 1) heating the clay at 800 oC for 6 hours (P-Clay), 2) mixing the P-Clay with KOH (K-Clay). An X-ray Fluorescence (XRF) showed the elemental composition of Ca-Clay contained Ca, Si, Al, and Fe. An X-ray Diffraction (XRD) showed the formation of highly crystalline CaO in the Ca-Clay with the main peak at 2θ = 37.27o. The Fourier Transform Infra Red (FTIR) spectrum showed an absorption peak in the range of 700-900 cm-1 indicating Ca-O stretching demonstrating successful incorporation of the CaO into the clay. The catalytic activity test showed the Ca-Clay had a higher catalytic performance than P-Clay and K-Clay in terms of the yield of biodiesel produced (73%). Copyright © 2020 BCREC Group. All rights reserved 

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