Study on the Synthesis of ZnO Nanoparticles Using Azadirachta indica Extracts for the Fabrication of a Gas Sensor

This paper compared the effects of A. indica plant proteins over chemical methods in the morphology of zinc oxide nanoparticles (ZnO NPs) prepared by a co-precipitation method, and ethanol sensing performance of prepared thin films deposited over a fluorene-doped tin oxide (FTO) bind glass substrate using spray pyrolysis technique. The average crystallite sizes and diameters of the grain-sized cluster ZnO NPs were 25 and (701.79 ± 176.21) nm for an undoped sample and 20 and (489.99 ± 112.96) nm for A. india dye-doped sample. The fourier transform infrared spectroscopy (FTIR) analysis confirmed the formation of the Zn–O bond at 450 cm−1, and also showed the presence of plant proteins due to A. indica dye extracts. ZnO NPs films exhibited good response (up to 51 and 72% for without and with A. indica dye-doped extracts, respectively) toward ethanol vapors with quick response-recovery characteristics at a temperature of 250 °C for undoped and 225 °C for A. indica dye-doped ZnO thin films. The interaction of A. indica dye extracts helps to decrease the operating temperature and increased the response and recovery rates of the sensor, which may be due to an increase in the specific surface area, resulting in adsorption of more oxygen and hence high response results.

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Trimethylamine and ethanol sensing properties of NiGa2O4 nano-materials prepared by co-precipitation method

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2017.09.012 ◽

2018 ◽

Vol 255 ◽

pp. 2058-2065 ◽

Cited By ~ 21

Author(s):

Xiangfeng Chu ◽

Jiulin Wang ◽

Linshan Bai ◽

Yongping Dong ◽

Wenqi Sun ◽

...

Keyword(s):

Precipitation Method ◽

Nano Materials ◽

Sensing Properties ◽

Ethanol Sensing ◽

Co Precipitation

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Crystal Structure, Lattice Strain, Morphology, and Electrical Properties of SnO2 Nanoparticles Induced by Low Calcination Temperature

Advances in Materials Science and Engineering ◽

10.1155/2020/3852421 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Panya Khaenamkaew ◽

Dhonluck Manop ◽

Chaileok Tanghengjaroen ◽

Worasit Palakawong Na Ayuthaya

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Calcination Temperature ◽

Tin Dioxide ◽

Lattice Strain ◽

Dielectric Constants ◽

Precipitation Method ◽

Calcination Temperatures ◽

Sensing Applications ◽

Crystallite Sizes

The electrical properties of tin dioxide (SnO2) nanoparticles induced by low calcination temperature were systematically investigated for gas sensing applications. The precipitation method was used to prepare SnO2 powders, while the sol-gel method was adopted to prepare SnO2 thin films at different calcination temperatures. The characterization was done by X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The samples were perfectly matched with the rutile tetragonal structure. The average crystallite sizes of SnO2 powders were 45 ± 2, 50 ± 2, 62 ± 2, and 65 ± 2 nm at calcination temperatures of 300, 350, 400, and 450°C, respectively. SEM images and AFM topographies showed an increase in particle size and roughness with the rise in calcination temperature. The dielectric constant decreased with the increase in the frequency of the applied signals but increased on increasing calcination temperature. By using the UV-Vis spectrum, the direct energy bandgaps of SnO2 thin films were found as 4.85, 4.80, 4.75, and 4.10 eV for 300, 350, 400, and 450°C, respectively. Low calcination temperature as 300°C allows smaller crystallite sizes and lower dielectric constants but increases the surface roughness of SnO2, while lattice strain remains independent. Thus, low calcination temperatures of SnO2 are promising for electronic devices like gas sensors.

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Nitrogen and Bromide Co-Doped Hydroxyapatite Thin Films with Antimicrobial Properties

Coatings ◽

10.3390/coatings11121505 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1505

Author(s):

Simona Liliana Iconaru ◽

Carmen Steluta Ciobanu ◽

Daniela Predoi ◽

Mikael Motelica-Heino ◽

Constantin Cătălin Negrilă ◽

...

Keyword(s):

Thin Films ◽

Antimicrobial Activity ◽

Spin Coating ◽

Thin Layers ◽

Precipitation Method ◽

X Ray ◽

Co Precipitation ◽

First Time ◽

Co Doped

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp), due to its high biocompatibility, is widely used as biomaterial. Doping with various ions of hydroxyapatite is performed to acquire properties as close as possible to the biological apatite present in bones and teeth. In this research the results of a study performed on thin films of hydroxyapatite co-doped with nitrogen and bromine (NBrHAp) are presented for the first time. The NBrHAp suspension was obtained by performing the adapted co-precipitation method using cetyltrimethylammonium bromide (CTAB). The thin layers of NBrHAp were obtained by spin-coating. The stability of the NBrHAp suspension was examined by ultrasound measurements. The thin layers obtained by the spin-coating method were examined by scanning electron microscopy (SEM), optical microscopy (OM), and metallographic microscopy (MM). The presence of nitrogen and bromine were highlighted by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) studies. Fourier transform infrared spectroscopy (FTIR) was used to highlight the chemical status of nitrogen and bromine. In addition, the powder obtained from the NBrHAp suspension was analyzed by XRD. Moreover, the in vitro antimicrobial activity of the NBrHAp suspensions and coatings was investigated using the reference microbial strains Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231. The results highlighted the successful obtainment of N and Br co-doped hydroxyapatite suspension for the first time by an adapted co-precipitation method. The obtained suspension was used to produce pure NBrHAp composite thin films with superior morphological properties. The NBrHAp suspensions and coatings exhibited in vitro antimicrobial activity against bacterial and fungal strains and revealed their good antimicrobial activity.

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Synthesis of Uniform Barium Ferrite Powders by Co-Precipitation Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1649 ◽

2017 ◽

Vol 898 ◽

pp. 1649-1654 ◽

Cited By ~ 1

Author(s):

Min Chen ◽

Run Hua Fan ◽

Zi Dong Zhang ◽

Yan Sheng Yin ◽

Li Hua Dong

Keyword(s):

Calcination Temperature ◽

Barium Ferrite ◽

Water Bath ◽

Precipitation Method ◽

Ammonium Bromide ◽

Barium Ferrites ◽

Hexagonal Barium Ferrite ◽

Crystallite Sizes ◽

Co Precipitation ◽

Hexadecyltrimethyl Ammonium Bromide

The uniform hexagonal barium ferrite powders were synthesized by co-precipitation method using metal chloride. The effects of the amount of hexadecyltrimethyl ammonium bromide (CTAB), the water bath and calcination temperature on the phase formation, microstructure and density of barium ferrites were systematically investigated. The results showed that the formation of uniform hexagonal barium ferrite powders was significantly influenced by the amount of CTAB and the water bath could lead to the larger grain size and density. The SEM demonstrated that the BaFe12O19 powders had plate-like shape with crystallite sizes varing from 150 to 200 nm. When the amount of CTAB was 0.2g/100ml and the calcination temperature was 850 °C, the barium ferrite powders were uniform which indicated that the amount of surfactant and calcination temperature were very optimum.

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Sonochemical Co-Precipitation Synthesis of Gallic Acid-Modified Magnetite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1101.286 ◽

2015 ◽

Vol 1101 ◽

pp. 286-289 ◽

Cited By ~ 2

Author(s):

Maya Rahmayanti ◽

Sri Juari Santosa ◽

Sutarno

Keyword(s):

Magnetic Properties ◽

Gallic Acid ◽

Precipitation Method ◽

Vibrating Sample Magnetometer ◽

X Ray Diffraction ◽

X Ray ◽

One Step ◽

The Fourier Transform ◽

The One ◽

Co Precipitation

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.

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Influence of ZrO2 Nanoparticles on the Microstructural Development of Cement Mortars with Limestone Aggregates

Applied Sciences ◽

10.3390/app9030598 ◽

2019 ◽

Vol 9 (3) ◽

pp. 598

Author(s):

Danna Trejo-Arroyo ◽

Karen Acosta ◽

Julio Cruz ◽

Ana Valenzuela-Muñiz ◽

Ricardo Vega-Azamar ◽

...

Keyword(s):

Xrd Analysis ◽

Sem Analysis ◽

Precipitation Method ◽

Zro2 Nanoparticles ◽

Microstructural Development ◽

Cement Ratio ◽

Cement Mortars ◽

Crystallite Sizes ◽

Co Precipitation ◽

Two Stages

In this research, the effect of the addition of zirconium oxide-synthesized nanoparticles on the microstructural development and the physical–mechanical properties of cement mortars with limestone aggregates was studied. Zirconia nanoparticles were synthesized using the co-precipitation method. According to XRD analysis, a mixture of tetragonal (t) and monoclinic (m) zirconia phases was obtained, with average crystallite sizes around 15.18 and 17.79 nm, respectively. Based on the ASTM standards, a mixture design was obtained for a coating mortar with a final sand/cement ratio of 1:2.78 and a water/cement ratio of 0.58. Control mortars and mortars with ZrO2 additions were analyzed for two stages of curing of the mortar—7 and 28 days. According to SEM analysis, mortars with ZrO2 revealed a microstructure with a high compaction degree and an increase in compressive strength of 9% on the control mortars. Due to the aggregates’ characteristics, adherence with the cement paste in the interface zone was increased. It is suggested that the reinforcing effect of ZrO2 on the mortars was caused by the effect of nucleation sites in the main phase C–S–H and the inhibition of the growth of large CH crystals, and the filler effect generated by the nanometric size of the particles. This produced a greater compaction volume, suggesting that faults are probably originated in the aggregates.

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Carboxymethylchitosan/Calcium Phosphate Hybrid Materials Prepared by an Innovative Auto-Catalytic Co-Precipitation Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.284-286.701 ◽

2005 ◽

Vol 284-286 ◽

pp. 701-704 ◽

Cited By ~ 1

Author(s):

S.A. Costa ◽

J. Miguel Oliveira ◽

Isabel B. Leonor ◽

Rui L. Reis

Keyword(s):

Calcium Phosphate ◽

Calcium Phosphates ◽

Precipitation Method ◽

Porous Scaffolds ◽

X Ray Diffraction ◽

Polymer Precipitation ◽

Acid Bath ◽

The Fourier Transform ◽

Xrd Patterns ◽

Co Precipitation

In this study, it is shown that it is possible to prepare carboxymethyl-chitosan/Ca-P hybrids using an innovative “auto-catalytic” co-precipitation method, namely by using an acid and an oxidant bath. The X-ray diffraction (XRD) patterns evidenced the formation of crystalline calcium-phosphate precipitates when using an acid bath, while amorphous ones were obtained for those produced in the oxidant bath. The Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM/EDS) studies revealed that the extent of the polymer precipitation and formation of calcium-phosphates is directly dependent on the pH and composition of the baths. Furthermore, by conducting bioactivity tests in a simulated body fluid (SBF) followed by the SEM/EDS analysis it was possible to detect the formation of an apatite layer with a cauliflower-like morphology on the surface of hybrids prepared by the acid bath, after 7 days of immersion. These results are quite promising because they can allow for the production of bioactive and biodegradable 3D porous scaffolds to be used in bone tissue engineering applications.

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Effect of silver doping on structural and photocatalytic circumstances of ZnO nanoparticles

Iraqi Journal of Nanotechnology ◽

10.47758/ijn.vi1.22 ◽

2020 ◽

pp. 13-20

Author(s):

Luma Ahmed ◽

Eitemad S. Fadhil ◽

Ayad F. Mohammed

Keyword(s):

Zno Nanoparticles ◽

Precipitation Method ◽

Methyl Green ◽

Zno Nanoparticle ◽

Zno Nps ◽

Force Microscopy ◽

Ft Ir ◽

Doped Zno ◽

Co Precipitation ◽

Artificial Uv

This article describes the synthesis of ZnO nanoparticles (Nps) using the co-precipitation method and then calcinated at 500oC for 2 h. The photo activity of ZnO nanoparticles was examined in photo decolorization of methyl green dye under artificial UV -A light. This prepared photocatalyst (ZnO Np) was modified his surface by 2% Ag doped using the photo deposition method under inert gas for 3h. The characterization of undoped and 2% Ag doped ZnO Nps were estimated by Fourier-transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), and Atomic force microscopy (AFM). In FT-IR analysis, the new peaks occurred around 624-778 cm-1 confirmed the Ag really is doped on prepared ZnO Np. Based on data from XRD, the mean crystal size was reduced with doped the 2% Ag. The AFM images for the prepared photocatalysts ensure that the shapes of all samples are semi-spherical with nanometer size. Series of kinetics experiments were performed for the photocatalytic decolourization of methyl green dye using undoped and 2% Ag doped ZnO nanoparticle and found to be pseudo-first-order kinetics.

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Metal Based-oxide Nanoparticles Assisted the Uptake of the Essential Elements and Phytoremediation of Populus Alba : Essential Metabolic Processes and Genetic Stability

10.21203/rs.3.rs-947444/v1 ◽

2021 ◽

Author(s):

Mohamed F. Ahmed ◽

Mostafa A. Ibrahim ◽

Ahmed S. Mansour ◽

Ahmed N. Emam ◽

Ashraf B. Abd El-Razik ◽

...

Keyword(s):

Metal Oxides ◽

Chemical Properties ◽

Essential Elements ◽

Precipitation Method ◽

Populus Alba ◽

Root Number ◽

Zno Nps ◽

Significant Difference ◽

Co Precipitation ◽

And Control

Abstract The present study evaluated the phytoremediation activities of Populus alba upon using nano metal-based-oxides (i.e., Fe2O3, ZnO, and Mn2O3-NPs) as analogues of three main heavy metals Fe, Zn and Mn exist in soil as micronutrients at three different concentrations (i.e., 20, 40, and 60 mg/L) compared to the control. The as-prepared nanoparticles have been prepared via co-precipitation method. In addition, the physico-chemical properties were investigated using transmission electron microscopy, Fourier transform infrared spectra, X-ray diffraction and dynamic light scattering techniques. Overall, a significant difference in the biomass production-related parameters such as fresh weight, shoot length, root length, and root number compared to control upon the treatment with micronutrients-based nano-metal-oxides (i.e., Mn2O3 > Fe2O3 > ZnO NPs, respectively), except a significant increase in the root number of Populus alba plant upon their treatment with ZnO NPs compared to other prepared nano-metal-oxides and control. Also, a remarkable increase in the chlorophyll index was monitored upon treatment with Fe2O3 than other used Mn2O3 and ZnO NPs, respectively. Moreover, RAPD-PCR bioassays were applied and the actual 6 primers showed a genetic variation percentage of 34.17% indicating that Populus alba is highly genetically stable even in a highly contaminated environment/soil. All these data enhance the idea of using the Populus alba plant in phytoremediation and heavy metal uptake as micronutrients to clean up the surroundings.

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