The effect of the post-annealing temperature on the nano-structure and energy band gap of SnO2 semiconducting oxide nano-particles synthesized by polymerizing–complexing sol–gel method

2008 ◽  
Vol 403 (13-16) ◽  
pp. 2431-2437 ◽  
Author(s):  
M.-M. Bagheri-Mohagheghi ◽  
N. Shahtahmasebi ◽  
M.R. Alinejad ◽  
A. Youssefi ◽  
M. Shokooh-Saremi
2016 ◽  
Vol 846 ◽  
pp. 607-613
Author(s):  
Mohd Syafiq Zulfakar ◽  
Huda Abdullah ◽  
Wan Nasarudin Wan Jalal ◽  
Zalita Zainuddin ◽  
Sahbudin Shaari

SiO2 compound was introduced into zinc ferrite using formula (1-x)ZnFe2O4 – xSiO2 synthesized by sol-gel method where distilled water and citric acid was used as a solvent and binder agent. The produced samples were annealed at 450 °C for 1h. The AFM result analysis show that the average surface roughness and particle size decreased as the compositions of x was increased. XRD results analysis confirmed the formation of spinel structures with crystallite size within range 11.27 – 4.72 nm. UV-Vis analysis to determine the energy band gap of the (1-x)ZnFe2O4 – xSiO2 samples. It shows that the energy band gap increased as the composition of SiO2 was increased due to the dielectric properties of silicon dioxide. FTIR results analysis exhibit common band in the range of 400 – 4000 cm-1. The observed band near 2350 cm-1 shows the presence of oxygen-oxygen bond in the face centered cubic (fcc) crystal lattice of oxygen atoms. The addition of SiO2 into ZnFe2O4 will help to enhance the morphological structures and optical properties. This new proposed dielectric material can be used as dielectric substrate microstrip patch antenna.


2021 ◽  
Vol 100 (1) ◽  
pp. 89-100
Author(s):  
Sk Irsad Ali ◽  
Anjan Das ◽  
Dhanadeep Dutta ◽  
Ajit Das ◽  
Nagendranath Mahata ◽  
...  

2018 ◽  
Vol 7 (4.30) ◽  
pp. 538 ◽  
Author(s):  
Maytham Qabel Hamzah ◽  
Salim Oudah Mezan ◽  
Alaa Nihad Tuama ◽  
Abdullah Hasan Jabbar ◽  
Mohd Arif Agam

Synthetic polymer/TiO2 composite such as Polystyrene/TiO2 has become recent highly research materials due to its potential and significant application in various fields. we can tune the polymer and nanoparticles by different techniques such as change the materials concentration, Exposure of materials to laser radiation, Exposure of materials to laser radiation, especially in tuning the polystyrene/TiO2 composite energy band gap. In this review, several methods of preparation are briefly explored such as pan-milling, precipitation, melt compounding, dip-coating, solution cast, and sol-gel method. Some recent advancement that focuses on the two basic elements: polymer and TiO2 are also included especially discussing on photocatalytic degradation that introduces photon as manipulate parameter to tune the polymer/TiO2 composite energy band gap. Scanning electron microscope (SEM) analysis of various polymer/TiO2 (type n concentration) and Polystyrene/TiO2 (concentration and nanoparticles sizes) are the focus of the discussion before exposure to laser radiation as photodegradation source.   


Author(s):  
M. T. SARODE ◽  
P. N. SHELKE ◽  
S. D. GUNJAL ◽  
Y. B. KHOLLAM ◽  
M. G. TAKWALE ◽  
...  

TiO 2 thin films were deposited on glass substrates by sol-gel method. Nanocrystalline TiO 2 thin films were prepared at ambient conditions and titanium tetraisopropoxide [ C 12 H 28 O 4 Ti ] was used as a Ti -precursor. The effect of annealing temperature on optical properties of nanocrystalline TiO 2 thin films was studied. The as-deposited films were dried at 100 °C for 1 hr. The films formed were further heated in temperature between 200 and 500 °C for 1 hr. The films were characterized by different techniques: XRD, UV-visible spectroscopy, FTIR spectroscopy and FESEM. The characterization studies revealed that the films are crystallized as anatase phase and nano-structured with better optical properties α = 0.89 as compared to reported data. The optical measurement showed the indirect band gap between 3.31 and 3.35 eV with corresponding crystallite sizes between 8.9 and 3.7 nm. The FESEM image of film annealed at 400 °C showed spherical nanocrystalline structure of TiO 2 particles. The crystallite sizes obtained from FESEM image are found to be between 30 and 100 nm. It is also observed that refractive index of the film increases with increasing the annealing temperature. The smaller crystallite size gives larger band gap due to quantum size effects.


2016 ◽  
Vol 701 ◽  
pp. 159-163 ◽  
Author(s):  
Sheen Jeff Teh ◽  
Yew Keong Sin ◽  
Kah Yoong Chan ◽  
Nisha Kumari Devaraj

Zinc oxide (ZnO) colloid has drawn significant attention recently due to its wide range of potential applications such as photonic crystals, solar cells, sensors, and other optical devices. In this work, low cost sol-gel spin coating technique was employed to synthesis ZnO colloid. The influences of stirring speed and post annealing temperature on the properties of ZnO colloid was investigated. The structural and optical properties of ZnO colloid was characterized using field-emission scanning electron microscopy (FESEM) and ultraviolet-visible (UV-Vis) spectrophotometer, respectively. Subsequently, Tauc method was used to estimate the optical band gap of the ZnO colloid based on the optical transmittance data. The effects of the stirring speed and post annealing temperature on the structural and optical properties of ZnO colloid are revealed and discussed in this paper. It was found that ZnO colloid prepared by the stirring speed of 500rpm and 400°C post annealing temperature demonstrates the best dispersity quality of colloid system.


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