Synthesis of Fe3O4/TiO2 Nanocomposite as Photocatalyst in Photoreduction Reaction of CO2 Conversion to Methanol

2020 ◽  
Vol 840 ◽  
pp. 454-458
Author(s):  
Adya Rizky Pradipta ◽  
Kurniawan Mauludi ◽  
Indriana Kartini ◽  
Eko Sri Kunarti

TiO2 modified Fe3O4 nanocomposite as photocatalyst in CO2 indirect reduction was synthesized by an ultrasonic-assisted sol-gel method and its photocatalytic activity was studied as well. The modification of the TiO2 composite was attempted to modify titanium dioxide to have better performance as a photocatalyst. Magnetite synthesis was carried out by the sono-coprecipitation method with the addition of the capping agent. The magnetite was coated with TiO2 via the sol-gel method under ultrasonic irradiation. The products were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectrophotometry (FT-IR), transmission electron microscopy (TEM), and turbidimetry. The final product was also analyzed by diffuse reflectance UV-Visible (DR-UV) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). The product of indirect reduction was analyzed by gas chromatography-mass spectrometry (GC-MS). Photocatalytic reaction with Fe3O4/TiO2 nanocomposite produced a higher concentration of methanol than using TiO2. Methanol concentration produced from the photocatalytic reaction using TiO2 and Fe3O4/TiO2 was 6.63% and 16.82%.

2021 ◽  
Author(s):  
V Maphiri ◽  
L Melato ◽  
Mhlongo ◽  
TT Hlatshwayo ◽  
TE Motaung ◽  
...  

Abstract Un-doped and ZnAlxO(1.5x + 1):0.1% Tb3+ (ZAOT) nano-powders were synthesized via citrate sol-gel method. The Alx moles were varied in the range of 0.25 ≤ x ≤ 5.0. The X-ray powder diffraction (XRD) data revealed that for the x < 1.5, the prepared samples crystal structure consists of mixed phases of the cubic ZnAl2O4 and hexagonal ZnO phases, while for the x ≥ 1.5 the structure consists of single phase of cubic ZnAl2O4. This was confirmed by the Raman and Fourier-Transform Infrared (FTIR) vibrational spectroscopy. Scanning electron microscopy (SEM) showed that varying Alx moles influences the morphology while Transmission electron microscopy (TEM) shows the dual morphology at x < 1.5. The photoluminescence (PL) revealed intense and distinct emissions attributed to both the host and Tb3+ transitions. The emission intensity highly depends on the Alx moles. The International Commission on Illumination (CIE) colour chromaticity showed that the emission colour could be tuned by varying the Alx moles.


2013 ◽  
Vol 631-632 ◽  
pp. 399-403
Author(s):  
Xi Ming Luo ◽  
Fen Fen Li ◽  
Hong Tao Gao

Sm, Zr doped nanocrystalline TiO2 powers were prepared successfully by a facile ultrasonic assisted sol-gel method. The products were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. X-ray diffraction peaks could be assigned to anatase TiO2, which confirms the crystallinity of the as-prepared samples. The SEM images demonstrated that the crystalinity is formed with spherical aggregates with average diameters ranging from 10 to 20 nm. The photocatalytic activity was studied on the photocatalytic degradation of methyl orange (MO) aqueous solution irradiated with UV-visible light. Under UV-visible light irradiation, the photocatalytic performances of the doped samples were much better than that of pure TiO2, and the co-dopant showed highest. It demonstrated that a strong Sm-Zr synergistic interaction might play a decisive role in driving the excellent photocatalytic performance of TiO2.


2019 ◽  
Vol 64 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Behnam Khanizadeh ◽  
Morteza Khosravi ◽  
Mohammad A. Behnajady ◽  
Ali Shamel ◽  
Behrouz Vahid

In this study, La and Mg doped, and co-doped ZnO nanoparticles were prepared using the sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and N2 physisorption techniques. The XRD results indicated that the prepared nanoparticles can be well adopted by the hexagonal wurtzite structure crystal and there are no second impurity peaks. Studies of the FESEM, EDX and TEM have shown that the samples have uniform spherical-like morphology with a homogenous distribution. The incorporation of La and Mg into the ZnO lattice had no effect on the morphology of the nanoparticles, but a reduction in the size of the grains (≈ 14 nm to ≈ 7 nm) was observed due to the insertion of these ions. The results of N2 physisorption indicated that there was an increase in BET surface area and pore volume for doped and co-doped samples. The results of DRS showed an increase in band gap energy and a blue shift at the absorption edge for doped and co-doped samples. The photocatalytic activity of the prepared catalysts was evaluated in the removal of RhB under UVA irradiation. The results showed that Mg5%-La5%/ZnO had the highest photoactivity (91.18 %) among all samples.


2012 ◽  
Vol 1494 ◽  
pp. 253-258
Author(s):  
Dan Jiang ◽  
Songwei Han ◽  
Xuelian Zhao ◽  
Jinrong Cheng

ABSTRACTBa0.6Sr0.4TiO3 (BST) thin films were deposited on La0.5Sr0.5CoO3 (LSCO) buffered Ti substrates. Both BST and LSCO were prepared by sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were used to investigate the effect of LSCO sol concentration on the crystallinity and surface morphology of the films. The results show that with the increase of LSCO sol concentration, BST films show variation of the structure and dielectric properties. BST films for LSCO of 0.2 mol/L exhibit a better crystallinity and improved dielectric properties, with the tunability, dielectric constant and tanδ of 30%, 420 and 0.028 respectively.


1996 ◽  
Vol 5 (1) ◽  
pp. 096369359600500 ◽  
Author(s):  
R. Rodríguez ◽  
J. Coreño ◽  
J.A. Arenas ◽  
V.M. Castaño

The growth of hydroxyapatite, a calcium phosphate, on silica particles prepared by the sol-gel method is reported. The size of the silica sols was controlled by changing the pH of water before the mixing with the alcoxide. Particle size profiles of sols were obtained by using dynamical light scattering. The characterisation of the composites, of nanometer sizes, was performed by employing X-ray diffraction, scanning electron microscopy and Raman spectroscopy.


2016 ◽  
Vol 254 ◽  
pp. 200-206 ◽  
Author(s):  
Catalina Nuțescu Duduman ◽  
María Isabel Barrena Pérez ◽  
José Maria Gómez de Salazar ◽  
Ioan Carcea ◽  
Daniela Lucia Chicet ◽  
...  

Nanostructured SnO2 was prepared based on the sol-gel method used in the preparation of crystalline metal oxides. Sol-gel process can be described as a forming network of oxide polycondensation reaction of a molecular precursor in a liquid. Six experiments were carried out. Morphological structures and chemical composition were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) after calcination. It is noted that TEM images show that the spheres consist from nanocrystals, quantitative EDS analysis of the chemical composition shows an absence of the chlorine, which is a desired fact. For structural characterization of the material we used X-Ray Diffraction (XRD). The X-ray diffraction pattern for all samples indicates peaks which are agreeable with standard diffraction pattern of SnO2. The particle size of all samples was in the range of 28-92 nm calculated according to Scherrer equation.


Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 774 ◽  
Author(s):  
Chihao Lin ◽  
Dejian Shi ◽  
Zhentao Wu ◽  
Lingfeng Zhang ◽  
Zhicai Zhai ◽  
...  

In this study, a bimetallic oxide catalyst of cobalt-manganese (CoMn2O4) was synthesized using the sol-gel method, and it was then characterized using a variety of techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) spectroscopy, X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption isotherms. The obtained novel catalyst, i.e., CoMn2O4, was then used as an activator of peroxymonosulfate (PMS) for the catalytic degradation of a commonly-used UV filter, 2-phenylbenzimidazole-5-sulfonic acid (PBSA) in water. The effects of various factors (e.g., catalyst dosage, PMS concentration, reaction temperature, and pH) in the process were also evaluated. Chemical scavengers and electron paramagnetic resonance (EPR) tests showed that the •OH and SO4•− were the main reactive oxygen species. Furthermore, this study showed that CoMn2O4 is a promising catalyst for activating PMS to degrade the UV filters.


2011 ◽  
Vol 335-336 ◽  
pp. 368-371 ◽  
Author(s):  
Yu Tie Bi ◽  
Hong Bo Ren ◽  
Bo Wei Chen ◽  
Lin Zhang

The synthesis and characterization of nickel-based aerogel prepared using nickel chloride as the precursor via sol-gel method is described. The addition of the polyacrylic acid as an template to the solution of NiCl2•6H2O can guide the gelation in the reaction to build a three dimensional open structure. The aerogel has been characterized using field emission scanning electron microscopy (FESEM), highresolution transmission electron microscopy (HRTEM), nitrogen adsorption desorption analysis and powder X-ray diffraction (XRD). The results indicate that the nickel-based aerogel has a typical three dimensional structure made up of spherical particles with an open porous network and has high surface area about 192 m2/g, average pore diameter about 40nm. The X-ray diffraction (XRD) patterns show that the aerogel prepared at room temperature belongs to amorphous material. The synthesis of nickel-based aerogel, using polyacrylic acid as an template, is especially unique in our experiment.


2019 ◽  
Vol 97 (4) ◽  
pp. 254-258 ◽  
Author(s):  
Fan Tong ◽  
Ye Zhao ◽  
Mao-Hua Wang

Pure and Na-doped ZnO (2 at.%, 5 at.%, and 10 at.%) films are synthesized by sol–gel method and annealed at 500 °C for 4 h. The as-synthesized nanoparticles are characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy (EDS). The samples exhibited hexagonal ZnO lattice structure and another Na2O2 phase was detected in the 5 at.% Na-doped ZnO sample. The calculated average crystalline size increases from 42.0 nm to 43.5 nm when Na content increased from 0 to 10 at.%. FESEM and TEM analysis identifies that the average size of the Na-doped ZnO nanoparticles lies in between 50 nm and they appear in spheroid-like or rod-like shaped particles. The transmittance of the sample was above 80% and the results of photocatalytic activity show that Na-doped ZnO nanoparticles exhibit higher photodegradation activity (about 91%) than pure ZnO nanoparticles under UV irradiation.


2014 ◽  
Vol 529 ◽  
pp. 108-111 ◽  
Author(s):  
Sheng Hao Meng ◽  
Yan Jun ◽  
Hong Guang Li ◽  
Shi Guo Du

Summarizd the methods of oxide coated on the surface of carbon nanotubes. Using carbon nanotubes (CNTs) as template, TiO2/CNTs nanocomposite was prepared by a sol-gel method. Urea as a promoter, obtained by the slow hydrolysis of tetrabutyl titanate Ti (OH)4 precursor is deposited on the carbon nanotubes, is further dehydrated to form TiO2. Its structure was characterized by X-ray energy spectroscopy (EDS) and scanning electron microscopy (SEM), and obtain uniform coating of TiO2/CNTs composites


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