Physical Properties Study of TiO2 Nanoparticle Synthesis via Hydrothermal Method Using TiO2 Microparticles as Precursor

2013 ◽  
Vol 772 ◽  
pp. 365-370 ◽  
Author(s):  
Mohd Hasmizam Razali ◽  
M.N. Ahmad-Fauzi ◽  
Abdul Rahman Mohamed ◽  
Srimala Sreekantan

Titanium dioxide (TiO2) nanoparticles were successfully synthesised by hydrothermal method using TiO2 microparticle powder (Merck) as precursor. TiO2 microparticles powder (~160 nm) was mixed with 10 M NaOH and treated hydrothermally at 150 °C and 2 MPa pressure in autoclave for 24 hours. After hydrothermal reaction was completed, the sample was washed, dried and heated at 500 °C for 2 hours to produce TiO2 nanoparticles. The synthesised nanoparticles were characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and raman spectroscopy. UV-Vis DRS was used to determine the band gap energy. Field emissions and transmissions electron microscopy images revealed that nanoparticles obtained was about 14 nm. X-ray diffraction patterns showed that TiO2 nanoparticles were anatase phase (tetragonal). The band gap energy of TiO2 nanoparticles was determined to be 3.32 eV.

2017 ◽  
Vol 889 ◽  
pp. 234-238
Author(s):  
Mohd Hasmizam Razali ◽  
Nur Arifah Ismail ◽  
Mahani Yusoff

Pure and F doped TiO2 nanotubes was synthesized using simple hydrothermal method. The hydrothermal was conducted using teflon-liner autoclave and maintained at 150oC for 24 hours. The characterization of synthesised product was carried out using x-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive of x-ray spectroscopy (EDX) and ultra violet – visible light diffuse reflectance spectroscopy (UV-Vis DRS) for band gap measurements. XRD patterns indicated that anatase TiO2 phase was remained after F doping suggested that fluorine was highly dispersed into TiO2 by substituted with O in the TiO2 lattice to formed TiO2-xFx solid solution. Morphology investigation using TEM found out small diameter of nanotubes structure within 8 – 10 nm of pure and F doped TiO2 nanotubes. The band gap energy (Eg) of both nanotubes samples were almost similar proposing that F doping does not modify the band gap energy.


Author(s):  
Anuar Kassim ◽  
Tan Wee Tee ◽  
Ho Soon Min ◽  
Shanthi Monohorn ◽  
Saravanan Nagalingam

PbSe thin films are prepared by chemical bath deposition technique over microscope glass substrates from an aqueous acidic bath containing lead nitrate and sodium selenate. The influence of bath temperature on the properties of PbSe film is investigated. The X-ray diffraction analysis showed the deposited films were polycrystalline and having the (111) orientation. The surface morphology study revealed that the grains have cubic shape crystal. The band gap energy was decreased from 2.0 to 1.3 eV as the bath temperature was increased from 40 to 80°C. The films deposited at 80°C showed good crystallinity and uniformly distributed over the surface of substrate with larger grain sizes. Therefore, the optimum bath temperature is 80°C. Keywords: Lead selenide; X-ray diffraction; Band gap energy; Chemical bath deposition; Thin films DOI: 10.3126/kuset.v6i2.4021Kathmandu University Journal of Science, Engineering and Technology Vol.6. No II, November, 2010, pp.126-132


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3427
Author(s):  
Is Fatimah ◽  
Gani Purwiandono ◽  
Putwi Widya Citradewi ◽  
Suresh Sagadevan ◽  
Won-Chun Oh ◽  
...  

In this work, photoactive nanocomposites of ZnO/SiO2 porous heterostructures (PCHs) were prepared from montmorillonite clay. The effects of preparation methods and Zn content on the physicochemical features and photocatalytic properties were investigated. Briefly, a comparison of the use of hydrothermal and microwave-assisted methods was done. The Zn content was varied between 5 and 15 wt% and the characteristics of the nanomaterials were also examined. The physical and chemical properties of the materials were characterized using X-ray diffraction, diffuse-reflectance UV-Vis, X-ray photoelectron spectroscopy, and gas sorption analyses. The morphology of the synthesized materials was characterized through scanning electron microscopy and transmission electron microscopy. The photocatalytic performance of the prepared materials was quantified through the photocatalytic degradation of methyl violet (MV) under irradiation with UV and visible light. It was found that PCHs exhibit greatly improved physicochemical characteristics as photocatalysts, resulting in boosting photocatalytic activity for the degradation of MV. It was found that varied synthesis methods and Zn content strongly affected the specific surface area, pore distribution, and band gap energy of PCHs. In addition, the band gap energy was found to govern the photoactivity. Additionally, the surface parameters of the PCHs were found to contribute to the degradation mechanism. It was found that the prepared PCHs demonstrated excellent photocatalytic activity and reusability, as seen in the high degradation efficiency attained at high concentrations. No significant changes in activity were seen until five cycles of photodegradation were done.


Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 589 ◽  
Author(s):  
Lin ◽  
Guo ◽  
Dai ◽  
Lin ◽  
Hsu

In this work, we used the chemical vapor transport (CVT) method to grow PbI2 crystals using iodine as a self-transporting agent. The crystals’ structure, composition, and uniformity were confirmed by X-ray diffraction (XRD) and electron probe microanalysis (EPMA) measurements. We investigated the band gap energy using absorption spectroscopy measurements. Furthermore, we explored the temperature dependence of the band gap energy, which shifts from 2.346 eV at 300 K to 2.487 eV at 20 K, and extracted the temperature coefficients. A prototype photodetector with a lateral metal–semiconductor–metal (MSM) configuration was fabricated to evaluate its photoelectric properties using a photoconductivity spectrum (PC) and persistent photoconductivity (PPC) experiments. The resonance-like PC peak indicates the excitonic transition in absorption. The photoresponse ILight/IDark-1 is up to 200%.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Nguyen Thi Truc Linh ◽  
Phan Dinh Tuan ◽  
Nguyen Van Dzung

The titania/hydroxyapatite (TiO2/HAp) product was prepared by precipitating hydroxyapatite in the presence of TiO(OH)2 gel in the hydrothermal system. The characteristics of the material were determined by using the measurements such as X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD), diffuse reflectance spectra (DRS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX). The XPS analysis showed that the binding energy values of Ca (2p1/2, 2p3/2), P (2p1/2, 2p3/2), and O 1s levels related to hydroxyapatite phase whereas those of Ti (2p3/2, 2p1/2) levels corresponded with the characterization of titanium (IV) in TiO2. The XRD result revealed that TiO2/HAp sample had hydroxyapatite phase, but anatase or rutile phases were not found out. TEM image of TiO2/HAp product showed that the surface of the plate-shaped HAp particles had a lot of smaller particles which were considered as the compound of Ti. The experimental band gap of TiO2/HAp material calculated by the DRS measurement was 3.6 eV, while that of HAp pure was 5.3 eV and that of TiO2 pure was around 3.2 eV. The shift of the band gap energy of TiO2 in the range of 3.2–3.6 eV may be related to the shifts of Ti signals of XPS spectrum.


2016 ◽  
Vol 846 ◽  
pp. 237-244
Author(s):  
Fakhrurrazi Ashari ◽  
Josephine Liew Ying Chyi ◽  
Zainal Abdib Talib ◽  
W. Wahmood Wan Yunus ◽  
Leong Yong Jian ◽  
...  

ZnSe which show a potential application in electronic devices such as photovoltaic devices, light emitting devices and photodetector have been synthesized through a hydrothermal method using ZnCl2 and Se powder as the source. In a typical synthesis, Zn2+ and Se2- ion have been prepared separately and charged into a Teflon-lined stainless steel autoclave. The hydrothermal reaction was conducted at 180 °C for 32 hours. Structural properties of ZnSe are studied by X-ray diffraction (XRD) while the optical properties of ZnSe compound are characterized through ultraviolet–visible spectroscopy (UV-Vis). From the XRD result, pure ZnSe with main XRD peak at 2θ = 27.29°, 45.30°, 53.62°, 65.88°, 72.68° has been observed. The result have been supported by the optical results where absoprtion peak at 460 nm with optical band gap energy (Eg) at 2.5 eV.


1996 ◽  
Vol 60 (402) ◽  
pp. 759-766 ◽  
Author(s):  
Laurent Van Haverbeke ◽  
Renaud Vochten ◽  
Karel Van Springel

AbstractChernikovite and meta-ankoleite were synthesized with a relatively high crystallinity and the compounds were identified by means of chemical analysis and X-ray diffraction. The infrared spectra were recorded and the bands assigned. From the luminescence spectra, the band-gap energy for both compounds was calculated as 2.35 eV, indicating that they must be considered as insulators. The dependence of the solubilities of these compounds on the acidity of the solution was studied, and the dominant ionic species were determined. The pKsp values of chernikovite and meta-ankoleite were found to be 22.73±0.24 and 24.30±0.81 respectively.


2019 ◽  
Vol 290 ◽  
pp. 323-328 ◽  
Author(s):  
Nor Fadilah Chayed ◽  
Norlida Kamarulzaman ◽  
Nurhanna Badar ◽  
Kelimah Elong

Doping of the materials with other metals or transition metals will modify the properties of the nanomaterials. In this work, MgO and Cu doped MgO which are Mg0.95Cu0.05O and Mg0.90Cu0.10O nanomaterials are synthesized using a self-propagating combustion method. The samples are annealed at 900 °C for 24 hours. The phase and purity of the synthesized samples are studied using X-Ray Diffraction (XRD) and the result revealed that the samples are pure and single phase. The morphology and crystallite size of the pure samples are examined using Field Emission Scanning Electron Microscope (FESEM). The result shows polyhedral morphology with agglomeration of crystallite and average crystallite size of the samples is between 40 to 210 nm. The band gap obtained for MgO nanostructures is 6.38 eV which is lower than bulk MgO of 7.8 eV. The presence of Cu causes the narrowing the band gap energy of Mg0.95Cu0.05O and Mg0.90Cu0.10O samples to 4.28 eV and 3.35 eV respectively.


2012 ◽  
Vol 545 ◽  
pp. 161-164
Author(s):  
Rusdi Roshidah ◽  
Abd Rahman Azilah ◽  
Norlida Kamarulzaman

ZnO is known as an inorganic material that has a variety of morphologies. The morphologies of the ZnO are much influenced by the synthesis route. In this work, two ZnO nanomaterials were prepared by the sol-gel route and the effect of detergent on the morphology and optical band gap of ZnO materials were investigated. The synthesized ZnO materials were characterized using Simultaneous Thermogravimetric Analyzer (STA), X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The UV-Vis spectrophotometer is used to determine the optical band gap. The results show that the presence of detergent affected the morphology of the ZnO from nanorods to nano-flakes. The band gap energy of the ZnO were also reduced from 3.14 ev to 2.98 eV from the nanorod to the nanoflakes.


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