scholarly journals The Influence of pH Values on the Crystallite Size of ZnO by Solvothermal Synthesis

2017 ◽  
Vol 2 (2) ◽  
pp. 118 ◽  
Author(s):  
Ahmadi Jaya Permana ◽  
Dian Wulandari ◽  
Hartati Hartati ◽  
Harsasi Setyawati ◽  
Mochammad Zakki Fahmi

 Zinc oxide (ZnO) is a semiconductor material that widely used in various applications due to its unique properties. Synthesis of ZnO by solvothermal method has been conducted with controlled pH values. The variations of pH value were 10, 11 and 12 by adjusting NaOH content. Crystall structure of the synthesis products after heat treatment at 110oC and 600oC has characterised by X-ray Diffratometer (XRD). Crystallite size of ZnO was measured by Scherrer equation. Crystall phase of ZnO has been observed on all pH value variations at 110 oC with 22,98-37,06 nm of crystallite size, whereas ZnO has been observed on all pH value variations at 600 oC with 41,39-71,77 nm of crystallite size.Keywords: ZnO, pH values, crystallite size, solvothermal

2011 ◽  
Vol 391-392 ◽  
pp. 1132-1137
Author(s):  
Su Ping Huang ◽  
Jun Zhu ◽  
Ke Chao Zhou

Luminescence behaviors and morphology of Eu3+doped hydroxyapatite synthesized under different pH values were well investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Inductively Coupled Plasma (ICP) (ICP–PLASMA 1000), and photoluminescence (PL) spectroscopy. Results revealed that With pH values increased from 6.5 to 10.0, the morphology of nano-Eu:HA particles changes from rod particles to equiaxed particles. The actual doping concentration and aspect ratio of Eu3+-doped HA decreased with the increasing of pH value. At the same time, the fluorescence intensity also tends to weakly lower with the increasing of pH value, which indicated that the luminescence properties mainly depended on the actual Eu3+doping concentration, the influences of morphology on the luminescence properties were slight.


2014 ◽  
Vol 15 ◽  
pp. 36-39 ◽  
Author(s):  
E Otgonjargal ◽  
G Burmaa ◽  
B Enkhmaa ◽  
M Enkhtuul ◽  
L Nyam-Ochir ◽  
...  

Mg/Al layered double hydroxide (LDH) was successfully synthesized at different pHs values. The Mg/AL LDH was well characterized by X-Ray diffraction and Fourier transform infrared analysis. The morphology of the LDH was observed using Scanning electron microscopy with energy dispersive X-ray spectroscopy. The influence of pH values on the morphology of the Mg/Al LDHs were studied. The result showed that the well-synthesized Mg/Al LDHs could be obtained when the pH value was about 10.0 at room temperature.DOI: http://doi.dx.org/10.5564/mjc.v15i0.319 Mongolian Journal of Chemistry 15 (41), 2014, p36-39


2012 ◽  
Vol 454 ◽  
pp. 324-328
Author(s):  
Yan He ◽  
Ya Jing Liu ◽  
Yong Lin Cao ◽  
Li Xia Zhou

Infra-red absorption spectrometry, X-ray diffraction observations and characterization tests based on silicon molybdenum colorimetric method were used to investigate the optimal pH value controlling the stability of the silicic acid form. The experiment process was done by using sodium silicate as raw material. The results showed that the solution of silicate influenced the polymerization. The active silicic acid solution with a certain degree of polymerization was obtained by controlling the pH values.


2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.


2018 ◽  
Vol 177 ◽  
pp. 01002
Author(s):  
Zhazgul Kelgenbaeva ◽  
Zhypargul Abdullaeva ◽  
Bektemir Murzubraimov

We present Au@Fe3O4 nanoparticles obtained from Fe nanoparticles and HAuCl4 using a simple solvothermal method. Trisodium citrate (C6H5Na3O7*2H2O) served as a reducing agent for Au. X-ray diffraction analysis, electronic microscopes and energy-dispersive X-ray spectroscopy revealed cubic structure, elemental composition (Au, Fe and O) and spherical shape of nanoparticles. Antibacterial activity of the sample was tested against E. coli bacteria and obtained results were discussed.


2019 ◽  
Vol 807 ◽  
pp. 1-10 ◽  
Author(s):  
Guang Xi Xu ◽  
Xiao Tong Sang ◽  
Jing Bao Lian ◽  
Nian Chu Wu ◽  
Xue Zhang

Eu3+ and Tb3+ ions singly activated Gd2O2S hollow spheres have been successfully synthesized via solvothermal method by using Gd (NO3)3, Eu (NO3)3, Tb (NO3)3 and thiourea as raw materials. Detailed characterization of the as-prepared samples were obtained by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), transmission electronic microscope (TEM) and photoluminescence (PL) spectroscopy. The results demonstrate that at 220 oC for 24 h, the molar ratio of thiourea/Gd3+ has no significant impact on the phase composition of Gd2O2S products. With the reaction time increased from 6 h to 24 h, the morphology of Gd2O2S samples changed from ellipsoidal to near-spheroidal structure, but still remained hollow structure. PL results show that the strongest emission peaks for Gd2O2S:Eu3+ and Gd2O2S:Tb3+ samples were centered at 625 nm and 545 nm, corresponding to the 5D0→7F2 transition of Eu3+ ions and 5D4→7F5 transition of Tb3+ ions, respectively. The quenching concentrations for Eu3+ and Tb3+ ions were 12% and 6%, which can be attributed to the exchange interaction for Eu3+ and Tb3+ ions, respectively.


CrystEngComm ◽  
2014 ◽  
Vol 16 (25) ◽  
pp. 5681-5688 ◽  
Author(s):  
Yu Zhang ◽  
Weiwei Ju ◽  
Xiao Xu ◽  
Yun Lv ◽  
Dunru Zhu ◽  
...  

Two mixed europium–yttrium MOFs with different interesting structures and doping proportions have been successfully synthesized by adjusting the pH values. The pH value largely affects the topologies and Eu/Y ratios of the two compounds.


2008 ◽  
Vol 22 (18n19) ◽  
pp. 3153-3158 ◽  
Author(s):  
M. R. BARATI ◽  
S. A. SEYYED EBRAHIMI ◽  
A. BADIEI

In this research a sol-gel auto-combustion route has been proposed to synthesize nickel-zinc ferrite nanocrystalline powder, using metal nitrates, citric acid as fuel and ammonia as pH adjusting agent. The influence of pH value of the solution on phase evolution, crystallite size and morphology of as-burnt powders were investigated by XRD, SEM and TEM techniques. The results revealed that with pH=7 the single phase nickel-zinc ferrite nanocrystalline powders with crystallite size of about 27nm were formed directly after auto combustion process.


2013 ◽  
Vol 829 ◽  
pp. 912-916 ◽  
Author(s):  
Alireza Khanaki ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard

Nanocrystalline CuInSe2 (CIS) powders were synthesized with a simple open-air solvothermal method as well as under conditions of applying internal imposed pressure. No post-treating processes such as annealing or selenization were used in both methods. The synthesis processes involved the reaction of precursors in an autoclave for different process times. Structural, morphological, and opto-electronic properties of CIS powders were compared. X-ray diffraction patterns (XRD) confirmed the formation of chalcopyrite structure of CIS powders in both approaches at reaction temperature of 220 °C and for short process time. Field emission scanning electron microscopy (FESEM) results show that while CIS powders synthesized under the atmospheric condition are mostly agglomerated, particles have more specific shapes in samples synthesized under internal imposed pressure. Furthermore, the band gap energies of synthesized CIS powders were obtained using diffuse reflectance UV-vis spectroscopy (DRS) measurements.


2010 ◽  
Vol 03 (02) ◽  
pp. 125-129 ◽  
Author(s):  
CAIQUAN ZHANG ◽  
YALI CUI ◽  
DIDI ◽  
KUNPING YAN ◽  
CHAO CHEN ◽  
...  

Facile procedures to synthesize large quantities of uniform and well dispersed magnetite particles in water were developed through a solvothermal method. Magnetite microspheres were obtained by using FeCl 3 · 6H 2 O , urea and polyethylene glycol as the starting materials in ethylene glycol at 200°C for 8 h. The samples were characterized by using X-ray diffraction, transmission electron microscopy, scanning electron microscopy and vibrating sample magnetometry. Experimental results revealed that the particles were well dispersed with uniform particle size and diameters in the range 260 to 280 nm. The saturation magnetization value was 71.5 emu/g with negligible remanence.


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