scholarly journals Copper-Iron Oxide: A Highly Effective Photocatalyst Than TiO2 Prepared by One-Step Sparking Process

2021 ◽  
Author(s):  
Arisara Panthawan ◽  
Nidchamon Jumrus ◽  
Panupong Sanmuangmoon ◽  
Winai Thongpan ◽  
Tewasin Kumpika ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Iron Oxide ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Composite Films ◽  
Energy Band Gap ◽  
Optimum Ratio ◽  
Different Temperatures ◽  
One Step ◽  
Photocatalytic Applications

Abstract Copper-iron (Cu-Fe) oxide composite films were successfully deposited on quartz substrate by a facile sparking process. The nanoparticles were deposited on the substrate after sparking off the Fe and Cu tips with different ratios and were then annealed at different temperatures. The network particles was observed after annealed the film at 700°C. Meanwhile, XRD and SAED patterns of the annealed films at 700°C consisted of a mixed phase of CuO, γ-Fe2O3, CuFe2O4 and CuFe2O. The film with a lowest energy band gap (Eg) of 2.56 eV was observed after anneal at 700°C. Interestingly, the optimum ratio and annealing temperature show highly photocatalytic activity than annealed TiO2 at 500 and 700°C. This is a novel photocatalyst which can be replace TiO2 for photocatalytic applications in the future.

scholarly journals Influence of Cu on the Improvement of Magnetic Properties and Structure of L10 FePt Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1097
Author(s):  
Luran Zhang ◽  
Xinchen Du ◽  
Hongjie Lu ◽  
Dandan Gao ◽  
Huan Liu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Reduction Method ◽  
Solid Phase ◽  
Average Particle Size ◽  
Fept Nanoparticles ◽  
Average Particle ◽  
Phase Reduction ◽  
Different Temperatures ◽  
One Step

L10 ordered FePt and FePtCu nanoparticles (NPs) with a good dispersion were successfully fabricated by a simple, green, one-step solid-phase reduction method. Fe (acac)3, Pt (acac)2, and CuO as the precursors were dispersed in NaCl and annealed at different temperatures with an H2-containing atmosphere. As the annealing temperature increased, the chemical order parameter (S), average particle size (D), coercivity (Hc), and saturation magnetization (Ms) of FePt and FePtCu NPs increased and the size distribution range of the particles became wider. The ordered degree, D, Hc, and Ms of FePt NPs were greatly improved by adding 5% Cu. The highest S, D, Hc, and Ms were obtained when FePtCu NPs annealed at 750 °C, which were 0.91, 4.87 nm, 12,200 Oe, and 23.38 emu/g, respectively. The structure and magnetic properties of FePt and FePtCu NPs at different annealing temperatures were investigated and the formation mechanism of FePt and FePtCu NPs were discussed in detail.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

scholarly journals Hydrothermally growth of TiO2 Nanorods, characterization and annealing temperature effect

2021 ◽  
Vol 48 (3) ◽  
Author(s):  
Nada Falih M ◽  
◽  
Saleem Azara Hussain ◽  
Shawki Khalaf Muhammad ◽  
Adel H. Omran Alkhayatt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Surface Topography ◽  
Hydrothermal Method ◽  
Annealing Temperature ◽  
Tio2 Nanorods ◽  
Energy Band Gap ◽  
Conductive Glass ◽  
Photocatalytic Applications ◽  
Morphology Changes

Titanium dioxide TiO2 nanorods were successfully grown on conductive glass FTO substrate using the hydrothermal method at a temperature of 160 oC. Surface topography, structure, and optical characteristics were studied according to the influence of annealing temperature (450, 550, and 650) oC. The surface topography results reveal that the TiO2 had nanorods structure with a tetragonal shape, and the rod diameter increases from 84.2 nm to 116.6 nm with increasing the annealing temperature. The crystal structure of the grown TiO2 NRs exhibits a high crystallinity of polycrystalline nature with anatase and rutile phases. The preferential orientation was along (204) plane for anatase tetragonal structure. AFM image shows an intense edge, uniform surface morphology, and increased grain diameter with annealing temperature. The optical properties of TiO2 NRs were investigated, and the absorption edge shows a blue shifting as the annealing temperature increases when considering the crystallinity and morphology changes. The energy band gap was found to be lower than 3 eV, which can be attributed to the presence of anatase and rutile phases with an increment range from 2.72 to 2.86 nm alongside the increase in the annealing temperature. The results indicate that the adopted hydrothermal method and the synthesized TiO2 NRs were suitable for photovoltaic and photocatalytic applications.

SYNTHESIS AND CHARACTERIZATION OF Au/ZnO NANOCOMPOSITES

2001 ◽  
Vol 15 (17n19) ◽  
pp. 679-682 ◽  
Author(s):  
U. PAL ◽  
E. AGUILA ◽  
O. VAZQUEZ ◽  
N. KOSHIZAKI ◽  
T. SASAKI ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Annealing Temperature ◽  
Composite Films ◽  
Synthesis And Characterization ◽  
Subsequent Change ◽  
Nanocomposite Thin Films ◽  
Different Temperatures ◽  
Average Size ◽  
Gold Wires

Au/ZnO nanocomposite thin films were prepared by co-sputtering of ZnO and gold. The Au content in the films was varied by varying the length of gold wires on the ZnO target. Depending upon the Au content in the films, the Au nanoparticles of different average size values were formed in the ZnO matrix. The composite films were annealed at different temperatures to study the evolution of Au particles and the subsequent change in their optical properties. With the increase of Au content in the films, the size of the nanometric Au particles decreased but increased with the increase of annealing temperature.

Synthesis and Characterization of SnO2-TiO2 Nanocomposites Photocatalysts

2019 ◽  
Vol 15 (4) ◽  
pp. 398-406 ◽  
Author(s):  
Charfeddine Messaadi ◽  
Taher Ghrib ◽  
Jalila Jalali ◽  
Mondher Ghrib ◽  
Alanood Abdullah Alyami ◽  
...  
Keyword(s):  
Grain Size ◽  
Photocatalytic Activity ◽  
Porous Silicon ◽  
Annealing Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
Methyl Blue ◽  
Gel Method ◽  
Sol Gel Method ◽  
Different Temperatures

Background: The photocatalytic activity of SnO2-TiO2 nanocomposites was successfully assessed after synthesis by Sol-Gel method, deposition on porous silicon material and annealing at 400, 600 and 800oC temperatures, with surface grain size in the range between 5 and 12 nm. The photocatalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (SEM), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and mass spectroscopy (MS). The photocatalytic assessment suggests that this SnO2-TiO2 photocatalyst presents important photocatalytic efficiency to methyl blue (MB) at low annealing temperature. </P><P> Methods: In this work, sol-gel method is used to prepare SnO2-TiO2 nanocomposites; which were deposited on porous silicon, annealed at different temperatures and investigated to understand their structural, morphological, optical and physical properties. Their photocatalytic activity was evaluated by using the degradation of MB under irradiation with UV light. </P><P> Results: The intensity of the characteristic absorption band of methyl blue at 655 nm decreased significantly with the increasing irradiation time. Meanwhile, a change in color of the solution occurred; turning from blue to colorless after 20 min of irradiation, and thus indicating the gradual decomposition of methyl blue molecules during UV light irradiation in the presence of the prepared SnO2-TiO2. As expected, no degradation of the SnO2-TiO2 nanocomposites occurred under control experimental conditions. The MB degradation efficiency was reported by C/C0 quantity; where C and C0 correspond respectively to its concentration at time t and initial concentration. In the presence of photocatalysts, it can be clearly deduced that after irradiation for 20 min, the C/C0 of the MB value was about 0% with the prepared and untreated nanocomposites of SnO2-TiO2 and remains constant when using a SnO2-TiO2 nanocomposite treated at 800°C. </P><P> Conclusion: This research has successfully synthesized the SnO2-TiO2 nanocomposite photocatalysts by Sol-Gel process and deposited by spin–coating technique on porous silicon substrates. Besides, all structural, optical and catalytic properties were studied and CO related. The obtained material was annealed at three different temperatures 400&#176;C, 600&#176;C and 800&#176;C. It is denoted that its grain size increases from about 5 nm to 12 nm with the annealing temperature. The photocatalytic effect has been tested on the MB solution, which demonstrates that the nanometric grain size enhances the adsorption properties and achieves a good photocatalytic performance at a low temperature.

scholarly journals Optical, Electrical and Photocatalytic Properties of the Ternary SemiconductorsZnxCd1-xS,CuxCd1-xSandCuxZn1-xS

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sandra Andrea Mayén-Hernández ◽  
David Santos-Cruz ◽  
Francisco de Moure-Flores ◽  
Sergio Alfonso Pérez-García ◽  
Liliana Licea-Jiménez ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Photocatalytic Properties ◽  
Energy Band Gap ◽  
Amorphous Thin Films ◽  
Semiconductor Thin Films ◽  
Different Temperatures ◽  
Blue Solution ◽  
Ternary Semiconductor ◽  
Van Der Pauw

The effects of vacuum annealing at different temperatures on the optical, electrical and photocatalytic properties of polycrystalline and amorphous thin films of the ternary semiconductor alloysZnxCd1-xS,CuxCd1-xSandCuxZn1-xSwere investigated in stacks of binary semiconductors obtained by chemical bath deposition. The electrical properties were measured at room temperature using a four-contact probe in the Van der Pauw configuration. The energy band gap of the films varied from 2.30 to 2.85 eV. The photocatalytic activity of the semiconductor thin films was evaluated by the degradation of an aqueous methylene blue solution. The thin film ofZnxCd1-xSannealed under vacuum at 300°C exhibited the highest photocatalytic activity.

FERROMAGNETISM IN SEMICONDUCTOR C–Ni FILMS AT DIFFERENT ANNEALING TEMPERATURE

2016 ◽  
Vol 23 (03) ◽  
pp. 1650002 ◽  
Author(s):  
VALI DALOUJI ◽  
SMOHAMMAD ELAHI
Keyword(s):  
Coercive Field ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Composite Films ◽  
Nickel Concentration ◽  
Maximum Value ◽  
Different Temperatures ◽  
The Difference ◽  
Quartz Substrates ◽  
Microstructure And Magnetic Properties

In this work, the microstructure and magnetic properties of carbon–nickel (C–Ni) composite films annealed at different temperatures (300–1000[Formula: see text]C) were investigated. The films were grown by radio frequency magnetron sputtering on quartz substrates at room temperature. The nickel concentration in the films are affected by changing of the value of evaporation nickel atoms and measured by Rutherford backscattering spectroscopy (RBS). Values of coercive field were measured under both increasing and decreasing applied magnetic field. It is shown that the coercive field of films strongly dependent on the annealing temperature and at 500[Formula: see text]C films has maximum value of 93.67[Formula: see text]Oe. The difference in the coercive fields increased for films annealed from 300 to 500[Formula: see text]C and then decreased from 500 to 1000[Formula: see text]C. The ID/IG ratio of Raman spectra would indicate the presence of higher sp2 bonded carbon in the films annealed at 800[Formula: see text]C.

Droplet Factories: Synthesis and Assembly of Silver and Palladium Nanoparticles at the Liquid-Liquid Interface

2019 ◽  
Author(s):  
Suchanuch Sachdev ◽  
Rhushabh Maugi ◽  
Sam Davis ◽  
Scott Doak ◽  
Zhaoxia Zhou ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Reaction Rate ◽  
Tertiary Structure ◽  
Flow Reactor ◽  
Pd Nanoparticles ◽  
Subsequent Removal ◽  
Immiscible Liquids ◽  
Flow Reactors ◽  
Droplet Flow ◽  
One Step

<div>The interface between two immiscible liquids represent an ideal substrate for the assembly of nanomaterials. The defect free surface provides a reproducible support for creating densely packed ordered materials. Here a droplet flow reactor is presented for the synthesis and/ or assembly of nanomaterials at the interface of the emulsion. Each droplet acts as microreactor for a reaction between decamethylferrocene (DmFc) within the hexane and metal salts (Ag+/ Pd2+) in the aqueous phase. The hypothesis was that a spontaneous, interfacial reaction would lead to the assembly of nanomaterials creating a Pickering emulsion. The subsequent removal of the solvents showed how the Ag nanoparticles were trapped at the interface and retain the shape of the droplet, however the Pd nanoparticles were dispersed with no tertiary structure. To further exploit this, a one-step process where the particles are synthesised and then assembled into core-shell materials was proposed. The same reactions were performed in the presence of oleic acid stabilise Iron oxide nanoparticles dispersed within the hexane. It was shown that by changing the reaction rate and ratio between palladium and iron oxide a continuous coating of palladium onto iron oxide microspheres can be created. The same reaction with silver, was unsuccessful and resulted in the silver particles being shed into solution, or incorporated within the iron oxide micro particle. These insights offer a new method and chemistry within flow reactors for the creation of palladium and silver nanoparticles. We use the technique to create metal coated iron oxide nanomaterials but the methodology could be easily transferred to the assembly of other materials.</div><div><br></div>

scholarly journals Photocatalytic activity of TiO2–P25@n-TiO2@HAP composite films for air depollution

2021 ◽  
Author(s):  
Guy Didier Fanou ◽  
Mamadou Traore ◽  
Benjamin Kouassi Yao ◽  
Andrei Kanaev ◽  
Khay Chhor
Keyword(s):  
Photocatalytic Activity ◽  
Composite Films
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