Nanocrystalline composites of transition metal molybdate (Ni Co MoO ; x = 0, 0.3, 0.5, 0.7, 1) synthesized by a co-precipitation method as humidity sensors and their photoluminescence properties

This paper presents the luminescence properties of dysprosium (Dy) doped calcium sulfate (CaSO4) phosphor material produced by co-precipitation technique with 0.1 - 0.5 mol% concentration of dopant. The crystallinity of the produced powder was studied using x-ray powder diffraction (XRD). The XRD spectrum shows high purity anhydrite CaSO4 phosphor material produced. The average crystallite size of 74 nm with orthorhombic crystal system was obtained. The luminescence behavior of produced CaSO4: Dy was studied using a photoluminescence (PL) spectrometer. The excitation and emission spectrum peaks associated with defects and vacancies of the phosphor material at claimed crystalline phase. The mixed peaks of excitation and emission that corresponds to micro and nano sized particle was shown for the produced powders. These properties show that the produced powders have wide range of luminescence detection with many electron traps ready for thermoluminescence (TL) information storage.

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Photocatalytic Activity of Zeolite Supported Transition Metal-(Co2+ and Cr2+) Doped ZnO: Comparative Study

Materials Science Forum ◽

10.4028/www.scientific.net/msf.827.43 ◽

2015 ◽

Vol 827 ◽

pp. 43-48

Author(s):

Annisa Noorhidayati ◽

Mia Putri Rahmawati ◽

Nadia Febiana Djaja ◽

Rosari Saleh

Keyword(s):

Transition Metal ◽

Zno Nanoparticles ◽

Diffuse Reflectance Spectroscopy ◽

Uv Light ◽

Transition Metal Ions ◽

Precipitation Method ◽

X Ray Diffraction ◽

X Ray ◽

Doped Zno ◽

Co Precipitation

Transition metal ions (Co and Cr) doped ZnO nanoparticles supported on natural zeolite were synthesized using co-precipitation method. The synthesized samples were characterized by means of X-ray diffraction, energy dispersive X-ray, Fourier-transform infrared absorption, and UV-visible diffuse reflectance spectroscopy. The samples were further used as photocatalyst for degradation of methyl orange and methylene blue in aqueous solutions under UV light irradiation. The results showed that zeolite supported Cr-doped ZnO nanoparticles is more efficient compared with zeolite supported Co-doped ZnO nanoparticles. It is also revealed that zeolite supported samples possessed higher photocatalytic efficiency compared to bare samples.

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Comparative Study on the Microstructure and Photoluminescence Properties of SnO2 Nano Particles Prepared by Different Methods

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.719-720.132 ◽

2015 ◽

Vol 719-720 ◽

pp. 132-136 ◽

Cited By ~ 3

Author(s):

Ghazaleh Allaedini ◽

Siti Masrinda Tasirin ◽

Meor Zainal Meor Talib ◽

Payam Aminayi ◽

Ifa Puspasari

Keyword(s):

Sol Gel ◽

Spherical Shape ◽

Nano Particles ◽

Precipitation Method ◽

Photoluminescence Properties ◽

X Ray Diffraction ◽

Gel Method ◽

Sol Gel Method ◽

Significant Difference ◽

Co Precipitation

This study presents comparisons between the morphologies and photoluminescence properties of tin oxide (SnO2) nanoparticles prepared by two methods, namely the sol gel and the co-precipitation methods. The characteristics of the particles were analyzed using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The particles prepared using the sol-gel method have a finer particle size and more spherical shape. However, no significant difference was observed in terms of morphology and homogeneity in the samples produced by either the co-precipitation or sol-gel methods. In contrast, the photoluminescence study shows that the emission peak for powder prepared using the sol-gel method was higher than that of the co-precipitation method.

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Fabrication and characterisation of nanocrystalline composites of Ca1−xCoxMoO4 (x = 0, 0.3, 0.5, 0.7, 1) prepared by co-precipitation method as a humidity sensor

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-016-5956-5 ◽

2016 ◽

Vol 28 (4) ◽

pp. 3548-3559 ◽

Cited By ~ 1

Author(s):

V. Jeseentharani ◽

B. Jeyaraj ◽

A. Dayalan ◽

K. S. Nagaraja

Keyword(s):

Humidity Sensor ◽

Precipitation Method ◽

Nanocrystalline Composites ◽

Co Precipitation

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Behavior of Layered Double Hydroxides Having Different Divalent Transition Metal Groups

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.563.94 ◽

2014 ◽

Vol 563 ◽

pp. 94-101 ◽

Cited By ~ 2

Author(s):

Mazidah Mamat ◽

Tei Tagg ◽

Wan Mohd Khairul ◽

Mohd Aidil Adhha Abdullah ◽

Norhayati Mohd Tahir ◽

...

Keyword(s):

Weight Loss ◽

Transition Metal ◽

Layered Double Hydroxides ◽

Divalent Cations ◽

Precipitation Method ◽

Basal Spacing ◽

Highest Weight ◽

Ft Ir ◽

Co Precipitation ◽

Double Hydroxides

The layered double hydroxides (LDHs) with different divalent transition metal groups and nitrate as a counter anion were investigated. Three d-block divalent metals namely cobalt (Co), nickel (Ni) and copper (Cu) were selected. The cobalt/aluminium (CoAN)-, nickel/aluminium (NiAN)- and copper/aluminium (CuAN)-layered double hydroxides were successfully synthesized via co-precipitation method. All the obtained LDHs were characterized by PXRD, FT-IR, ICP-OES, CHNS and TGA/DTG analysis. Interestingly, behavior of the LDHs was dependent on the size of divalent cations. PXRD showed the basal spacing decrease in the order NiAN (0.88nm)> CuAN (0.87nm) > CoAN (0.74nm), and in a linear correlation with the increasing radii of the divalent cations. Similar trend is observed for the weight loss of LDHs, where NiAN has the highest weight loss (53%), followed by CuAN (43%) and CoAN (34%). Further elemental analysis showed the content of trivalent metal cations, nitrate anions and water molecules in the LDHs decrease with the increasing radii.

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