scholarly journals The Influence of Calcination Temperature on the Formation of Zinc Oxide Nanoparticles by Thermal-Treatment

2013 ◽  
Vol 446-447 ◽  
pp. 181-184 ◽  
Author(s):  
Naif Mohammed Al-Hada ◽  
Elias Saion ◽  
A.H. Shaari ◽  
M.A. Kamarudin ◽  
Salahudeen A. Gene

Zinc oxide nanoparticles were synthesized by the thermal-treatment method. Polyvinyl pyrrolidone was used as capping agent and Zinc nitrate was used as a precursor. The samples were calcined at 500 and 550°C for removal of the organic compounds. The structural characteristics of the calcined samples were examined by X-ray diffraction and transmission electron microscopy. The results show that the average particle size increases with increase in calcination temperature. The optical properties were characterized at room temperature using a UV–Vis spectrophotometer in the wavelength range between 200–800 nm and the band gap energy was calculated from reflectance spectra using kubalka munk function and the results indicated that the band gap energy decreased from 3.23 eV at 500 oC to 3.21 eV at 600 °C due to an increase of particle size. This simple thermal-treatment method has advantages of the pure nanoparticles formation as no additional chemicals were required, a lack of by-product effluents, and environmentally friendly process.

2017 ◽  
Vol 268 ◽  
pp. 132-137 ◽  
Author(s):  
Anwar Ali Baqer ◽  
Khamirul Amin Matori ◽  
Naif Mohammed Al-Hada ◽  
Abdul Halim Shaari ◽  
Elias Saion ◽  
...  

A sample thermal treatment technique was utilised to synthesis cerium dioxide (CeO2) nanoparticles, using cerium (111) nitrate as a precursor, Polyvinylpyrrolidone as a capping agent, and deionized water as a solvent. The product underwent calcination treatment of 500, 550, 600, and 650 1C to crystallize the nanoparticles and to remove organic compounds. It was verified by XRD that by varying the calcination temperature, the cubic fluorite structure of CeO2 nanoparticles with pure products was achieved. Furthermore, the crystal sizes of the CeO2 nanoparticles were assessed to be 4 nm for the lowest calcination temperature and 23 nm for the highest calcination temperature. The FESEM micrographs of the CeO2 nanoparticles revealed a structure of CeO2 nanospherical that exhibited a tendency to amalgamate at higher calcination temperatures. The optical characteristics that were evaluated with the help of a UV-Vis spectrophotometer indicated a decrease in the band gap energy with an increase in calcination temperature as a result of the increase in the crystal sizes.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Salahudeen A. Gene ◽  
Elias Saion ◽  
Abdul H. Shaari ◽  
Mazliana A. Kamarudin ◽  
Naif M. Al-Hada ◽  
...  

The present study reports the structural and magnetic characterization of spinel zinc chromite (ZnCr2O4) nanocrystallines synthesized by thermal treatment method. The samples were calcined at different temperatures in the range of 773 to 973 K. Polyvinylpyrrolidone was used to control the agglomeration of the nanoparticles. The average particle size of the synthesized nanocrystals was determined by powder X-ray diffraction which shows that the crystallite size increases from 19 nm at 773 K to 24 nm at 973 K and the result was in good agreement with the transmission electron microscopy images. The elemental composition of the samples was determined by energy dispersed X-ray spectroscopy which confirmed the presence of Zn, Cr, and O in the final products. Fourier transform infrared spectroscopy also confirmed the presence of metal oxide bands for all the samples calcined at different temperature. The band gap energy was calculated from UV-vis reflectance spectra using the Kubelka-Munk function and the band gap energy of the samples was found to decrease from 4.03 eV at 773 K to 3.89 eV at 973 K. The magnetic properties were also demonstrated by electron spin resonance spectroscopy, the presence of unpaired electrons was confirmed, and the resonant magnetic field and theg-factorof the calcined samples were also studied.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1118
Author(s):  
Ibrahim Mustapha Alibe ◽  
Khamirul Amin Matori ◽  
Mohd Hafiz Mohd Zaid ◽  
Salisu Nasir ◽  
Ali Mustapha Alibe ◽  
...  

The contemporary market needs for enhanced solid–state lighting devices has led to an increased demand for the production of willemite based phosphors using low-cost techniques. In this study, Ce3+ doped willemite nanoparticles were fabricated using polymer thermal treatment method. The special effects of the calcination temperatures and the dopant concentration on the structural and optical properties of the material were thoroughly studied. The XRD analysis of the samples treated at 900 °C revealed the development and or materialization of the willemite phase. The increase in the dopant concentration causes an expansion of the lattice owing to the replacement of larger Ce3+ ions for smaller Zn2+ ions. Based on the FESEM and TEM micrographs, the nanoparticles size increases with the increase in the cerium ions. The mean particles sizes were estimated to be 23.61 nm at 1 mol% to 34.02 nm at 5 mol% of the cerium dopant. The optical band gap energy of the doped samples formed at 900 °C decreased precisely by 0.21 eV (i.e., 5.21 to 5.00 eV). The PL analysis of the doped samples exhibits a strong emission at 400 nm which is ascribed to the transition of an electron from localized Ce2f state to the valence band of O2p. The energy level of the Ce3+ ions affects the willemite crystal lattice, thus causing a decrease in the intensity of the green emission at 530 nm and the blue emission at 485 nm. The wide optical band gap energy of the willemite produced is expected to pave the way for exciting innovations in solid–state lighting applications.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 115
Author(s):  
Suhail Huzaifa Jaafar ◽  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Sidek Hj. Ab Aziz ◽  
Halimah Mohamed Kamari ◽  
...  

This research paper proposes the usage of a simple thermal treatment method to synthesis the pure and Eu3+ doped ZnO/Zn2SiO4 based composites which undergo calcination process at different temperatures. The effect of calcination temperatures on the structural, morphological, and optical properties of ZnO/Zn2SiO4 based composites have been studied. The XRD analysis shows the existence of two major phases which are ZnO and Zn2SiO4 crystals and supported by the finding in the FT-IR. The FESEM micrograph further confirms the existence of both ZnO and Zn2SiO4 crystal phases, with progress in the calcination temperature around 700–800 °C which affects the existence of the necking-like shape particle. Absorption humps discovered through UV-Vis spectroscopy revealed that at the higher calcination temperature effects for higher absorption intensity while absorption bands can be seen at below 400 nm with dropping of absorption bands at 370–375 nm. Two types of band gap can be seen from the energy band gap analysis which occurs from ZnO crystal and Zn2SiO4 crystal progress. It is also discovered that for Eu3+ doped ZnO/Zn2SiO4 composites, the Zn2SiO4 crystal (5.11–4.71 eV) has a higher band gap compared to the ZnO crystal (3.271–4.07 eV). While, for the photoluminescence study, excited at 400 nm, the emission spectra of Eu3+ doped ZnO/Zn2SiO4 revealed higher emission intensity compared to pure ZnO/Zn2SiO4 with higher calcination temperature exhibit higher emission intensity at 615 nm with 700 °C being the optimum temperature. The emission spectra also show that the calcination temperature contributed to enhancing the emission intensity.


2021 ◽  
Vol 21 (7) ◽  
pp. 3795-3799
Author(s):  
Mi-Young Ha ◽  
Chang Kyo Kim ◽  
Dae-Gyu Moon

Zinc oxide nanoparticles (ZnO NPs) have been widely used as an inorganic electron transport layer (ETL) in quantum dot light-emitting devices (QLEDs) due to their excellent electrical properties. Here, we report the effect of ZnO NPs inorganic ETL of different particle sizes on the electrical and optical properties of QLEDs. We synthesized ZnO NPs into the size of 3 nm and 8 nm respectively and used them as an inorganic ETL of QLEDs. The particle size and crystal structure of the synthesized ZnO NPs were verified by Transmission electron microscopy (TEM) analysis and X-ray pattern analysis. The device with 8 nm ZnO NPs ETL exhibited higher efficiency than the 3 nm ZnO NPs ETL device in the single hole transport layer (HTL) QLEDs. The maximum current efficiency of 19.0 cd/A was achieved in the device with 8 nm ZnO NPs layer. We obtained the maximum current efficiency of 17.5 cd/A in 3 nm ZnO NPs device by optimizing bilayer HTL and ZnO NPs ETL.


2018 ◽  
Vol 93 ◽  
pp. 427-435 ◽  
Author(s):  
Patrick Mountapmbeme Kouotou ◽  
Achraf El Kasmi ◽  
Ling-Nan Wu ◽  
Muhammad Waqas ◽  
Zhen-Yu Tian

Vacuum ◽  
2011 ◽  
Vol 86 (2) ◽  
pp. 140-143 ◽  
Author(s):  
Prakash Thangaraj ◽  
Jayaprakash Rajan ◽  
Sathyaraj Durai ◽  
Sanjay Kumar ◽  
Ayalsomayajula RatnaPhani ◽  
...  

2020 ◽  
Vol 32 (4) ◽  
pp. 907-911
Author(s):  
S. Akash ◽  
N. Ahalya ◽  
P. Dhamodhar

Zinc oxide nanoparticles were synthesized using epicarp of Punica granatum by combustion method at moderate temperatures. Zinc oxide nanoparticles obtained in agglomerate form were characterized by powder X-ray diffractometer (PXRD) and found to have hexagonal phase, wurtzite structure. The crystalline size of nanoparticle was found to be ~ 60 nm by using Debye-Scherrer formula. The morphology Index, Lorentz factor and Lorentz polarization factor were also calculated. Ultraviolet-visible spectroscopy (UV-vis) spectrum for ZnO nanoparticle showed a strong absorbance at 374 nm. This corresponds to the calculated band gap energy of 3.48 eV and the particle size calculated using band gap was found to be 50 nm. The Fourier Transform Infrared Spectroscopy (FTIR) spectrum showed a peak at 499 cm-1, which indicated Zn-O stretch bond. The scanning electron microscopy (SEM) analysis proved the size of nanoparticles synthesized were around 50 nm and energy dispersive X-ray spectroscopy (EDS) revealed the elemental composition of zinc oxide nanoparticles. The ZnO-NPs were evaluated for antibacterial activity against gram positive, tonsillitis causing Streptococcus pyogenes. From the present study, it was concluded that zinc oxide nanoparticles synthesized by combustion method could be valuable and economic in the field of nanotechnology.


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