scholarly journals Synthesis and Application of Fe3O4/SiO2/TiO2 Nanocomposite as Photocatalyst in CO2 Indirect Reduction to Produce Methanol

2019 ◽  
Vol 19 (4) ◽  
pp. 827
Author(s):  
Yudha Ramanda ◽  
Nuryono Nuryono ◽  
Eko Sri Kunarti
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Average Diameter ◽  
Band Gap Energy ◽  
Indirect Reduction ◽  
Magnetic Photocatalyst ◽  
Specular Reflectance ◽  
Transmission Electron ◽  
Infrared Spectrophotometer ◽  
Magnetic Recoverability

This study focuses on the synthesis and application of a Fe3O4/SiO2/TiO2 nanocomposite as a photocatalyst in CO2 indirect reduction. The synthesis was started by preparation of magnetite (Fe3O4) followed by silica (SiO2) coating and titania (TiO2) deposition. Magnetite was prepared by the sono-coprecipitation method, then the coating of SiO2 and deposition of TiO2 were performed by the sol-gel method under ultrasonic irradiation. All the material products were characterized by an X-ray diffractometer (XRD), Fourier-transform infrared spectrophotometer (FTIR), and transmission electron microscope (TEM). The final material product was also analyzed by a specular reflectance UV-Visible spectrometer (SR-UV-Vis) and the turbidimetry method. The product of the indirect reduction was analyzed by a gas chromatography-mass spectrometer (GC-MS). The XRD diffractograms and FTIR spectra confirmed the presence of Fe3O4, SiO2, and the anatase phase of TiO2. The TEM images revealed the presence of a core-shell nanocomposite with an average diameter of 19.22 ± 1.25 nm. The SR-UV-Vis spectrum was used to determine the band gap energy of the photocatalyst, with the result being 3.22 eV. Turbidimetry aimed to measure the magnetic recoverability of the final material, and the result was that it had better recoverability compared to a non-magnetic photocatalyst composite. The GC chromatogram of the indirect reduction product indicated four majorfractions; the MS spectra showed these to be methanol, formaldehyde, formic acid, and CO2. The GC-MS results revealed that CO2 indirect reduction achieved 73.91% conversion of CO2 and 55.01% selective to methanol.

Synthesis of Fe3O4/TiO2-Co Nanocomposite as Model of Photocatalyst with Magnetic Properties

2017 ◽  
Vol 901 ◽  
pp. 14-19 ◽  
Author(s):  
Muhammad Ramadhan ◽  
Adya Rizky Pradipta ◽  
Eko Sri Kunarti
Keyword(s):  
Sol Gel ◽  
Band Gap Energy ◽  
Magnetic Photocatalyst ◽  
X Ray ◽  
Optimum Result ◽  
Specular Reflectance ◽  
Maximum Value ◽  
Infrared Spectrophotometer ◽  
Co Precipitation

Synthesis and characterization of Fe3O4/TiO2-Co as magnetic photocatalyst had been done. The research was started with the preparation of magnetite through co-precipitation and sonication system, followed by preparation of Co-dopedTiO2 using sol-gel method and then mixed both of them with a ratio of Fe3O4:TiO2 1:3; 1:9; 1:15 (FT3, FT9, FT15) and ended by calcination. The product was characterised by using Fourier transform infrared spectrophotometer (FTIR), X-ray diffractometer (XRD), scanning electron microscope-energy dispersive X-ray spectrophotometer (SEM-EDX), UV-Specular reflectance spectrophotometer (SR-UV) and vibrating sample magnetometer (VSM). The resulting material showed a maximum value of band gap energy at 2.83 eV in FT3. The effect of Fe3O4:TiO2 ratio known can be affected the magnetic moment and showed the optimum result 2.0 emu/g in FT3. The magnetic character of Fe3O4/TiO2-Co also known can be affected by the magnetite crystalline size from the composites composition.

scholarly journals Carboxymethyl Cellulose Photocracking by Magnetic Recoverable Photocatalyst to Produce Biofuel in Ambient Condition

2017 ◽  
Vol 5 (2) ◽  
pp. 90
Author(s):  
Yudha Ramanda ◽  
Kevin Thomas ◽  
Saifuddin Aziz ◽  
Kurniawan Mauludi ◽  
Eko Sri Kunarti
Keyword(s):  
Carboxymethyl Cellulose ◽  
Anatase Phase ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
Specular Reflectance ◽  
Transmission Electron ◽  
Ft Ir ◽  
Uv Visible

Synthesis of Fe3O4/SiO2/TiO2 nanocomposite and its application as photocatalyst in Carboxymethyl Cellulose (CMC) photocracking had been conducted. Magnetite preparation was carried out by sono-coprecipitation method. The deposition of SiO2 and TiO2 were performed by sol-gel method under ultrasonic irradiation. All material products were characterized by X-ray diffraction (XRD), Fourier transform infra-red spectrophotometry (FT-IR), and transmission electron microscopy (TEM). The final material product was also analysed by specular reflectance UV-Visible (SR-UV-Vis). The product of photocracking was analysed by gas chromatography – mass spectrometry (GC-MS).The XRD diffractogram and FT-IR spectra confirmed the presence of Fe3O4, SiO2, and anatase phase of TiO2. The TEM image revealed the presence of nanocomposite with core-shell structure. The SR-UV-Vis spectrum was used to determine band gap energy of the photocatalyst and it gave a result of 3.22 eV. The GC chromatogram of photocracking product indicated some major fractions. The MS spectra showed that some major fractions were smaller molecules including methanol, the component of biofuel.

scholarly journals Photocatalytic antibacterial performance of TiO2and Ag-doped TiO2againstS. aureus.P. aeruginosaandE. coli

2013 ◽  
Vol 4 ◽  
pp. 345-351 ◽  
Author(s):  
Kiran Gupta ◽  
R P Singh ◽  
Ashutosh Pandey ◽  
Anjana Pandey
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Annealed Sample ◽  
Bacterial Strains ◽  
X Ray Diffraction ◽  
Photoexcited Electron ◽  
Antibacterial Performance ◽  
Transmission Electron ◽  
Vis Spectroscopy

This paper reports the structural and optical properties and comparative photocatalytic activity of TiO2and Ag-doped TiO2nanoparticles against different bacterial strains under visible-light irradiation. The TiO2and Ag-doped TiO2photocatalysts were synthesized by acid catalyzed sol–gel technique and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectroscopy and photoluminescence (PL). The XRD pattern revealed that the annealed sample of TiO2has both anatase and rutile phases while only an anatase phase was found in Ag-doped TiO2nanoparticles. The decreased band-gap energy of Ag-doped TiO2nanoparticles in comparison to TiO2nanoparticles was investigated by UV–vis spectroscopy. The rate of recombination and transfer behaviour of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. The antimicrobial activity of TiO2and Ag-doped TiO2nanoparticles (3% and 7%) was investigated against both gram positive (Staphylococcus aureus) and gram negative (Pseudomonas aeruginosa,Escherichia coli) bacteria. As a result, the viability of all three microorganisms was reduced to zero at 60 mg/30 mL culture in the case of both (3% and 7% doping) concentrations of Ag-doped TiO2nanoparticles. Annealed TiO2showed zero viability at 80 mg/30 mL whereas doped Ag-TiO27% showed zero viability at 40 mg/30 mL culture in the case ofP. aeruginosaonly.

Fabrication of TiO2-Aerogel with NiB Nano-Clusters and Its Structural Characterization and Catalysis Evaluation

2006 ◽  
Vol 11-12 ◽  
pp. 7-10
Author(s):  
T. Nishi ◽  
Sakae Tanemura ◽  
Lei Miao ◽  
Masaki Tanemura ◽  
K. Suzuki
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Ground Sample ◽  
Tio2 Anatase ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Infrared Spectrophotometer ◽  
Ft Ir ◽  
The Difference

We have prepared titania aerogel (=AG) embedded by NiB nano-clusters by sol-gel method, immersion of the prepared wet gel into the NiB dispersed solution, and the subsequent super critical drying (=SCD). The AG was characterized by X-ray diffraction (XRD), a transmission electron microscopy (TEM), and a fourier transform infrared spectrophotometer (FT-IR). XRD and selected area electron diffraction (SAED) patterns assured the formation of TiO2 anatase phase. TEM observation reveled the composition of TiO2 crystallites with about 4 nm in size. Catalyst performance for the ground sample was confirmed by chemical reaction of oxidation of benzene at low temperature, and the difference in catalyst performance between TiO2 AGs with and without the embedded NiB nano-clusters has been examined.

The Influence of Cu Dopant Concentration on the Optical Properties of Fe3O4/SiO2/TiO2 Nanocomposite

2019 ◽  
Vol 948 ◽  
pp. 260-266
Author(s):  
Aisyiah Restutiningsih Putri Utami ◽  
M. Sulthon Nurharman Syah Putra ◽  
M. Miqdam Musawwa ◽  
Eko Sri Kunarti
Keyword(s):  
Electron Microscope ◽  
Sol Gel ◽  
Aqueous Media ◽  
Band Gap Energy ◽  
X Ray ◽  
Optimum Result ◽  
Specular Reflectance ◽  
Transmission Electron ◽  
The Fourier Transform ◽  
Co Precipitation

Fe3O4/SiO2/TiO2dopped Cu with magnetic properties had been succesfully syntesized and characterized. The research was began with the synthesis of magnetite and magnetite covered by silica by co-precipitation and sonication method, and the preparation of Cu-doped TiO2using sol-gel method followed by calcination. The concentrations of Cu were 0%, 1%, 3%, 5%, and 7% (FST0, FST1, FST3, FST5, and FST7). The Fourier Transform Infra Red spectrophotometer (FTIR), X-Ray Diffractometer (XRD), Scanning Electron Microscope-Energy Dispersive X-ray spectrophotometer (SEM-EDX), UV-Specular Reflectance Spectrophotometer (SR-UV), and Transmission Electron Microscope (TEM) were used to characterize the nanocomposite and external magnetic bar was used to separate the nanocomposite in an aqueous media. The Cu concentration affected the band gap energy (Eg) and the optimum result was 2.832 eV in FST7. The best magnetic propertieswas material FST0. The time needed for separate this material with aqueous medium was 372 second.

scholarly journals Synthesis and Optical Manifestation of NiO-Silica Nanocomposite

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
S. Chakrabarty ◽  
K. Chatterjee
Keyword(s):  
Sol Gel ◽  
Size Variation ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Peak Position ◽  
Band Gap Energy ◽  
Strong Emission ◽  
Silica Nanocomposites ◽  
Composite Formation ◽  
Silica Nanocomposite

NiO-silica nanocomposites with average diameter ranging from 2–40 nm were prepared by sol-gel method followed by the heat treatment varying from 400°C to 1000°C. The details of morphology and crystalline nature of all the as prepared samples were characterized by TEM, HRTEM, and XRD analysis. The planes obtained from SAED pattern supports the planes originated from XRD study. From the optical absorption study, it is revealed that the band gap energy of NiO can extensively be manipulated by composite formation with silica and the size variation of that nanocomposite. Absorption peak position varies almost linearly with the oxidation temperature of the samples. Photoluminescence spectroscopy reveals that NiO-silica nanocomposite, prepared at 600°C and below, shows strong emission at 3.62 eV, but the nanocomposites with bigger size greatly hinder the effect of selective emissivity.

Synthesis, Characterization and Photocatalytic Property of Magnetic Titania Hollow Sphere Composite

2011 ◽  
Vol 298 ◽  
pp. 188-192
Author(s):  
Cong Zhang ◽  
Rong Hou ◽  
Hui Zhang
Keyword(s):  
Sol Gel ◽  
Hollow Spheres ◽  
Photocatalytic Property ◽  
High Photocatalytic Activity ◽  
Polystyrene Spheres ◽  
Magnetic Photocatalyst ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Anatase Titania ◽  
Tio2 Hollow Spheres

The magnetic anatase titania (TiO2) hollow spheres have been fabricated as magnetic photocatalyst by template (polystyrene)-sacrificed method, in which cobalt ferrite and titania was sequentially deposited on the surface of polystyrene spheres via coprecipitation and sol-gel process followed by calcinations. X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) were employed to characterize the products, and the photocatalytic activities were evaluated by photodegradation of methyl orange (MO) under UV illumination. The results indicate that the as-prepared magnetic titania hollow spheres exhibit magnetic property and high photocatalytic activity.

scholarly journals ZnFe2O4-TiO2Nanoparticles within Mesoporous MCM-41

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Aidong Tang ◽  
Yuehua Deng ◽  
Jiao Jin ◽  
Huaming Yang
Keyword(s):  
Sol Gel ◽  
Rutile Phase ◽  
Band Gap Energy ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Agglomeration Of Nanoparticles ◽  
Adsorption Desorption ◽  
Mcm 41

A novel nanocomposite ZnFe2O4-TiO2/MCM-41 (ZTM) was synthesized by a sol-gel method and characterized through X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N2adsorption-desorption, Raman spectroscopy, and ultraviolet visible (UV-vis) spectrophotometry. The results confirmed the incorporation of ZnFe2O4-TiO2nanoparticles inside the pores of the mesoporous MCM-41 host without destroying its integrity. ZnFe2O4nanoparticles can inhibit the transformation of anatase into rutile phase of TiO2. Incorporation of ZnFe2O4-TiO2within MCM-41 avoided the agglomeration of nanoparticles and reduced the band gap energy of TiO2to enhance its visible light photocatalytic activity. UV-vis absorption edges of ZTM nanocomposites redshifted with the increase of Zn/Ti molar ratio. The nanocomposite approach could be a potential choice for enhancing the photoactivity of TiO2, indicating an interesting application in the photodegradation and photoelectric fields.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

Nanocrystal TiO2 Engulfed SiO2-Barium Hexaferrite for Enhanced Electrons Mobility and Solar Harvesting Potential

2015 ◽  
Vol 819 ◽  
pp. 226-231
Author(s):  
Azrina Abd Aziz ◽  
Shaliza Ibrahim ◽  
Saravanan Pichiah
Keyword(s):  
Phase Transformation ◽  
Photocatalytic Activity ◽  
Magnetic Separation ◽  
Sol Gel ◽  
Visible Region ◽  
Barium Hexaferrite ◽  
Band Gap Energy ◽  
Magnetic Core ◽  
Magnetic Photocatalyst ◽  
Titania Photocatalyst

Barium hexaferrite embedded-silica-titania photocatalyst (TiO2-SiO2-BaFe12O19) was synthesized through sol-gel, liquid catalytic phase transformation and solid reaction routes. The magnetic photocatalyst was aimed to harvest the photoenergy from the sunlight, minimize the electron-holes recombination rate, improve the long lifetime charge-carriers transfer to maximize the photocatalytic activity and enhances the separation and reusability of it. The as-synthesized photocatalyst was characterized and the photocatalytic activity was evaluated for the reduction of 2, 4-dichlorophenol (2, 4-DCP) under direct sunlight. The presence of SiO2 interlayer in TiO2-SiO2-BaFe12O19 prevents the phase transformation of magnetic core. TiO2-SiO2-BaFe12O19 benefits the magnetic separation with appreciable magnitude of coercivity (5035.6 Oe) and saturation magnetization (18.8256E-3 emu/g), respectively. The ferrite ions from the magnetic core which dispersed into TiO2 matrix exhibited an evident shift of the absorption in the visible region. This was again confirmed with the reduced band gap energy of 1.90 eV. Furthermore, TiO2-SiO2-BaFe12O19 destructed 100% of 2, 4-DCP compound within 150 min under very bright sunlight with an average irradiance of 820.8 W/m2 (results not shown). The embedding of BaFe12O19 with a SiO2 layer onto TiO2 nanocrystals contributed for an excellent solar-light utilization and ease magnetic separation of the nanosized photocatalyst.

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