scholarly journals Preparation, Characterization and Optical Property of LaFeO3 Nanoparticles via Sol-Gel Combustion Method

2019 ◽  
Vol 1 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Mya Theingi ◽  
Kay Thi Tun ◽  
Nwe Nwe Aung
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Combustion Method ◽  
Crystal Formation ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Gel Method ◽  
Sol Gel Method ◽  
Lafeo3 Nanoparticles ◽  
Ft Ir

Perovskite LaFeO3 is one of the most useful materials for the application in a catalyst, gas sensors, and fuel cells, etc. LaFeO3 nanoparticles were synthesized by the citrate sol-gel method. According to the TG-DTA analysis on LaFeO3 xerogel powder, the proper crystallization temperature was found to be at 450 °C. The TEM images also show clear crystal formation was started at 450 °C. The LaFeO3 nanocrystalline particles were obtained by sintering the calcined powders at different temperatures (800 °C, 900 °C, and 1000 °C) for 4 hours. The resulting particles were characterized by XRD, EDXRF, FT IR, and SEM analysis. At 900 °C, the XRD pattern of LaFeO3 shows an orthorhombic crystal structure. The average crystallite sizes vary between 30-60 nm and the increase in crystallite size with increasing sintering temperatures and it may be due to the increase in grain growth. FT IR analysis shows strong La-O and Fe-O vibrations. Based on the XRD and FT IR data, the optimum sintering temperature was chosen at 900 °C. The SEM micrographs show that the morphology of LaFeO3 has small-sized grains with round shape. The optical properties were determined by UV-visible spectroscopy in the wavelength range of 300 nm-700 nm. The optical band gap energy values of LaFeO3 using Tauc’s plot were found to be about 2.45 eV. These results indicate that the LaFeO3 prepared by the sol-gel method has a relatively lower band gap value and so it can have the potential for photocatalytic applications.

Analysis Microstructure of La0.7(Sr1-xCax)0.3MnO3 Prepared by Sol-Gel Method

2020 ◽  
Vol 855 ◽  
pp. 140-144
Author(s):  
Sitti Ahmiatri Saptari ◽  
Redho Aulia Putra ◽  
Arif Tjahjono ◽  
Anugrah Azhar ◽  
Ikhwan Nur Rahman
Keyword(s):  
Crystal Structure ◽  
Dopant Concentration ◽  
Sol Gel ◽  
Orthorhombic Crystal ◽  
Structure Transition ◽  
Orthorhombic Crystal Structure ◽  
Gel Method ◽  
Space Group ◽  
Sol Gel Method ◽  
Ion Substitution

Perovskite-based on manganite La0.7(Sr1-xCax)0.3MnO3 (x = 0, 0.3, 0.5, 0.7) has been successfully synthesized using by sol-gel method. All sample was characterized by using XRD (X-Ray Diffraction) obtain a single phase without impurities peak. The transition of crystal structure transition, lattice parameters, cell unit volume, crystal size, bond length (Mn-O), and <Mn-O-Mn> bond angles caused by Ca2+ ion substitution. Dopant concentration x = 0 - 0.5 shows that the sample has a rhombohedral crystal structure with space group R-3c and orthorhombic crystal structure with space group P n m a at dopant concentration x = 0.7. The results of SEM (Scanning Electron Microscope) characterization show a difference in grain size with the addition of Ca2+ ion substitution.

scholarly journals Bismuth Oxide Prepared by Sol-Gel Method: Variation of Physicochemical Characteristics and Photocatalytic Activity Due to Difference in Calcination Temperature

2020 ◽  
Vol 21 (1) ◽  
pp. 108
Author(s):  
Yayuk Astuti ◽  
Brigita Maria Listyani ◽  
Linda Suyati ◽  
Adi Darmawan
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Calcination Temperature ◽  
Bismuth Oxide ◽  
Sol Gel ◽  
Physicochemical Characteristics ◽  
Band Gap Energy ◽  
Gel Method ◽  
Sol Gel Method ◽  
Body Center Cubic

Research on synthesis of bismuth oxide (Bi2O3) using sol-gel method with varying calcination temperatures at 500, 600, and 700 °C has been done. This study aims to determine the effect of calcination temperature on the characteristics of the obtained products which encompasses crystal structure, surface morphology, band-gap energy, and photocatalytic activity for the decolorization of methyl orange dyes through its kinetic study. Bismuth oxide prepared by sol-gel method was undertaken by dissolving Bi(NO3)3·5H2O and citric acid in HNO3. The mixture was stirred then heated at 100 °C. The gel formed was dried in the oven and then calcined at 500, 600, and 700 °C for 5 h. The obtained products were a pale yellow powder, indicating the formation of bismuth oxide. This is confirmed by the existence of Bi–O and Bi–O–Bi functional groups through FTIR analysis. All three products possess the same mixed crystal structures of α-Bi2O3 (monoclinic) and γ-Bi2O3 (body center cubic), but their morphologies and band gap values are different. The higher the calcination temperature, the larger the particle size and the smaller the band gap value. The accumulative differences in characteristics appoint SG700 to have the highest photocatalytic activity compared to SG600 and SG500 as indicated by its percent degradation value and decolorization rate constant.

Preparation of La0.75Sr0.25Cr0.5Mn0.5O3-δ Nanometer Powders by Sol-Gel Method and Research about its Electrochemical Performance

2013 ◽  
Vol 712-715 ◽  
pp. 257-261
Author(s):  
Yin Lin Wu ◽  
Qing Hui Wang ◽  
Ling Wang ◽  
Hai Yan Zhao
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Electrochemical Performance ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Preparation Process ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ft Ir

The La0.75Sr0.25Cr0.5Mn0.5O3-δnanometer powders were prepared by citric acid sol-gel method.The samples were characterized by DTA, FT-IR, XRD, TEM techniques. The preparation process, morphology of synthesized powders, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 800°C. The particle size is about 30nm and Ea is 0.071 eV.

Formation Nano Size Ag–TiO2 Composite by Sol–Gel Method and Investigation of Band Gap Decline

2013 ◽  
Vol 5 (10) ◽  
pp. 1039-1043 ◽  
Author(s):  
Mozhgan Hatami ◽  
K. Venkateswara Rao ◽  
Mohsen Ahmadipour ◽  
V. Rajendar
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Nano Size

Blueshift in optical band gap in nanocrystalline Zn1−xCaxO films deposited by sol-gel method

2009 ◽  
Vol 95 (3) ◽  
pp. 031901 ◽  
Author(s):  
Kamakhya Prakash Misra ◽  
R. K. Shukla ◽  
Atul Srivastava ◽  
Anchal Srivastava
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method

Preparation of TiO2/Bamboo Charcoal Photocatalysts with Sol-Gel Method

2012 ◽  
Vol 557-559 ◽  
pp. 1457-1460 ◽  
Author(s):  
Chang Bin Xia ◽  
Chun Hua Liu ◽  
Dao Xin Wu
Keyword(s):  
Ir Spectra ◽  
Sol Gel ◽  
Bamboo Charcoal ◽  
Gel Method ◽  
Sol Gel Method ◽  
Reflective Spectrum ◽  
Ft Ir ◽  
Bamboo Carbon

TiO2/bamboo charcoal complex photocatalysts has been prepared for tetra-n-butyltitanate as titanium source, bamboo carbon (BC) as the carrier with Sol-Gel method.it Characterizations were analyzed using TGA, DSC, SEM, XRD, DRS (diffuse reflective spectrum) and FT-IR spectra.

scholarly journals Growth and Spectral Investigation on Pure Calcium Phosphate Doped With (Copper and Magnesium) Crystals

2021 ◽  
pp. 322-332
Author(s):  
R. Selvaraju ◽  
M. Bhuvaneswari
Keyword(s):  
Calcium Phosphate ◽  
Sol Gel ◽  
Gallbladder Stone ◽  
Calcium Stones ◽  
Gel Method ◽  
Sol Gel Method ◽  
Gallbladder Stones ◽  
Dta Analysis ◽  
Ft Ir

Calcium stones are most commonly occurring form of cholelithiasis or gallbladder stones most one of the oldest and common afflictions of humans. Calcium phosphate is dissolved minerals in causes of renal to gallbladder stone in both human and animals. Of course, the calcium phosphate is one of the components of gallbladder. Calcium phosphate doped with (Cu and Mg) are crystals are grown by sol-gel method. In the present work the growth and characterization of pure and doped with (Cu and Mg) crystals. The grown crystals were characterization by FT-IR, SEM-EDX and TG/DTA analysis.

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