scholarly journals Fabrication of Reproducible and Selective Ammonia Vapor Sensor-Pellet of Polypyrrole/Cerium Oxide Nanocomposite for Prompt Detection at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1829
Author(s):  
Ahmad Husain ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Imran Khan ◽  
Mohammad Mujahid Ali Khan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cerium Oxide ◽  
Room Temperature ◽  
Ammonia Concentration ◽  
Electronic Interaction ◽  
Ammonia Vapor ◽  
X Ray Diffraction ◽  
Time Reversibility ◽  
Vapor Sensing ◽  
Ft Ir

Polypyrrole (PPy) and polypyrrole/cerium oxide nanocomposite (PPy/CeO2) were prepared by the chemical oxidative method in an aqueous medium using anhydrous ferric chloride (FeCl3) as an oxidant. The successful formulation of materials was confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmittance electron microscopy (TEM). A four-in-line probe device was used for studying DC electrical conductivity and ammonia vapor sensing properties of PPy and PPy/CeO2. The significant improvement in both the conductivity and sensing parameters of PPy/CeO2 compared to pristine PPy reveals some synergistic/electronic interaction between PPy and cerium oxide nanoparticles (CeO2 NPs) working at molecular levels. The initial conductivity (i.e., conductivity at room temperature) was found to be 0.152 Scm−1 and 1.295 Scm−1 for PPy and PPy/CeO2, respectively. Also, PPy/CeO2 showed much better conductivity retention than pristine PPy under both the isothermal and cyclic ageing conditions. Ammonia vapor sensing was carried out at different concentration (0.01, 0.03, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 vol %). The sensing response of PPy/CeO2 varied with varying concentrations. At 0.5 vol % ammonia concentration, the % sensing response of PPy and PPy/CeO2 sensor was found to be 39.1% and 93.4%, respectively. The sensing efficiency of the PPy/CeO2 sensor was also evaluated at 0.4. 0.3, 0.2, 0.1, 0.05, 0.03, and 0.01 vol % ammonia concentration in terms of % sensing response, response/recovery time, reversibility, selectivity as well as stability at room temperature.

scholarly journals Improving stability of cerium oxide nanoparticles by microbial polysaccharides coating

2018 ◽  
Vol 83 (6) ◽  
pp. 745-757 ◽  
Author(s):  
Ivana Milenkovic ◽  
Ksenija Radotic ◽  
Branko Matovic ◽  
Marija Prekajski ◽  
Ljiljana Zivkovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cerium Oxide ◽  
Aqueous Media ◽  
Suspension Stability ◽  
X Ray Diffraction ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Ft Ir ◽  
Microbial Exopolysaccharides ◽  
The Stability

Cerium oxide (CeO2) nanoparticles (CONPs) are interesting biomaterials with various applications in biomedicine, cosmetics and the pharmaceutical industry, but with limited practical application because of their low stability in aqueous media. The aim of this study was to obtain CONPs with increased stability by coating the particles. Microbial exopolysaccharides (levan, pullulan) and glucose were used to prepare CONPs under different synthesis conditions. Coating was attempted by adding the carbohydrates during (direct coating) or after (subsequent coating) the synthesis of CONPs. The obtained nanoparticles were characterized by X-Ray diffraction analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The suspension stability of the uncoated and coated CONPs in aqueous media was evaluated by measuring the hydrodynamic size, zeta potential and turbidity. The FT-IR spectra revealed the differences between coated CONPs and showed the success of subsequent coating with carbohydrates. Coating with carbohydrates improved the stability the CONP suspension by decreasing the size of aggregated particles. The suspensions of levan- and glucose-coated CONPs had the best stability. In this study, CONPs were prepared using non-toxic materials, which were completely environmentally friendly. The obtained results open new horizons for CONP synthesis, improving their biological applications.

scholarly journals A Simple and Facile Solvothermal Synthesis of Hierarchical PbS Microstars with Multidendritic Arms and Their Optical Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yong-Fang Li ◽  
Ming Zhang ◽  
Qi-Jing Yang ◽  
Feng-Xian Zhang ◽  
Mei-Qi Zheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Solar Absorbers ◽  
Transmission Electron ◽  
Ir Photodetectors ◽  
Ft Ir

A simple and facile approach was developed in the solvothermal synthesis of hierarchical PbS microstars with multidendritic arms, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and photoluminescence (PL) spectroscopy. The morphologies of PbS products were strongly determined by the reaction time and temperature, the ratios of the precursors, and the mixed solvent with various components, and thereby their possible formation mechanism was discussed in some detail. The as-prepared PbS crystals displayed a sharp and strong photoluminescent peak at 437 nm at room temperature. It has potential and practical applications in photoluminescence, photovoltaics, IR photodetectors, electroluminescence, and solar absorbers.

scholarly journals Effect of lead salts on phase, morphologies and photoluminescence of nanocrystalline PbMoO4 and PbWO4 synthesized by microwave radiation

2016 ◽  
Vol 34 (3) ◽  
pp. 529-533 ◽  
Author(s):  
Anukorn Phuruangrat ◽  
Budsabong Kuntalue ◽  
Surachai Artkla ◽  
Surin Promnopas ◽  
Wonchai Promnopas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Microwave Radiation ◽  
Room Temperature ◽  
Blue Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Salts ◽  
Transmission Electron ◽  
Ft Ir ◽  
Kinetics Of

AbstractPbMoO4 and PbWO4 were successfully synthesized by microwave radiation using different lead salts (acetate, chloride, nitrate and sulfate) and Na2MO4 (M = Mo, W) in propylene glycol. The products were characterized by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM), Fourier transform infrared (FT-IR), Raman spectroscopy and photoluminescence (PL) spectroscopy. In this research, morphologies, crystallization and photoluminescence of the products were influenced by the kinetics of anions, including the detection of M–O (M = Mo, W) stretching modes in the (MO4)2− tetrahedrons. Photoluminescence of PbMoO4 synthesized from Pb(NO3)2 and of PbWO4 synthesized from PbCl2 showed the strongest blue emission due to the electronic diffusion in tetrahedrons at room temperature.

DC electrical conductivity retention and acetone/acetaldehyde sensing on polythiophene/molybdenum disulphide composites

2021 ◽  
pp. 096739112110027
Author(s):  
Ahmad Husain ◽  
Sharique Ahmad ◽  
Shahid Pervez Ansari ◽  
Mohammad Omaish Ansari ◽  
Mohammad Mujahid Ali khan
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
Lone Pair ◽  
Electronic Interaction ◽  
X Ray Diffraction ◽  
Molybdenum Disulphide ◽  
Dc Electrical Conductivity ◽  
Conductivity Retention

In this study, polythiophene (PTh) and a series of polythiophene/molybdenum disulphide (PTh/MoS2) composites were prepared by in-situ chemical oxidative polymerization method using anhydrous ferric chloride (FeCl3) as an oxidant and chloroform (CHCl3) as a solvent. The successful formation of PTh and PTh/MoS2 composites were confirmed by various techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance electron microscopy (TEM). DC electrical conductivity and acetone/acetaldehyde sensing studies were carried out by a four-in-line probe device. PTh/MoS2 composites exhibited significantly improved DC electrical conductivity and acetone/acetaldehyde sensing properties as compared to PTh. The electrical properties were investigated in terms of initial conductivity (i.e. conductivity at room temperature) as well as retention of conductivity, i.e. stability under isothermal and cyclic ageing conditions. The maximum initial conductivity, along with the highest conductivity retention, was observed for PTh/MoS2-2 (PTh/MoS2 composite comprising 10% MoS2 with respect to the weight of thiophene monomer). The initial DC electrical conductivity of PTh, PTh/MoS2-1, PTh/MoS2-2 and PTh/MoS2-3 was found to be 5.72 × 10−5 Scm−1, 4.03 × 10−4 Scm−1, 1.09 × 10−3 Scm−1 and 8.96 × 10−4 Scm−1, respectively. The sensing performance at room temperature has been studied in terms of % sensing response, response/recovery time. All the PTh/MoS2 composites based sensors performed much better than PTh. The % sensing response of PTh, PTh/MoS2-1, PTh/MoS2-2 and PTh/MoS2-3 based pellet-shaped sensors towards acetone/acetaldehyde were affirmed as 30.6/22.9, 69.9/47.3, 93.7/70.3, 78.1/65.1, respectively. The purposed sensing mechanism involved the adsorption of acetone/acetaldehyde vapours on the surface of the sensors where electronic interaction between lone pair of electrons on oxygen atoms of the carbonyl group and charge carriers of PTh was responsible for the change in conductivity.

scholarly journals Template-Free Synthesis of Porous Cu2O Nanospheres at Room Temperature and Investigation on Their Adsorption Property

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Ying Zhang ◽  
Dong Wang ◽  
Xu Zhang ◽  
Fengyu Qu
Keyword(s):  
Electron Microscopy ◽  
Ir Spectrum ◽  
Room Temperature ◽  
Adsorption Property ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
20 Nm ◽  
Adsorption Desorption

Porous cuprous oxide (Cu2O) nanospheres composed of small nanoparticles with diameters at 10~20 nm were successfully synthesized without surfactant at room temperature within 5 min. The products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), N2adsorption-desorption, and Fourier transform infrared (FT-IR) spectrum. The adsorption ability of the as-prepared products towards methyl orange (MO) as the pollutant was investigated and FT-IR spectrum was employed to identify the adsorbed species. In addition, the reusability of the as-prepared products was studied as well.

Synthesis and characterization of polypyrrole/molybdenum oxide composite for ammonia vapour sensing at room temperature

2021 ◽  
pp. 096739112110365
Author(s):  
Mohd Urooj Shariq ◽  
Ahmad Husain ◽  
Mahfoozurrahman Khan ◽  
Anees Ahmad
Keyword(s):  
Electron Microscopy ◽  
Molybdenum Oxide ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Composite ◽  
Ammonia Vapour ◽  
Ft Ir ◽  
Adsorption Desorption

In this study, polypyrrole (PPy) and polypyrrole/molybdenum oxide composite (PPy/MoO3) were synthesized by the chemical oxidative method in an aqueous medium, using anhydrous ferric chloride (FeCl3) as an oxidant. The successful preparation of materials was confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance electron microscopy (TEM). PPy and PPy/MoO3 were converted into pellets which were used as the sensor. A four-in-line probe device was used for studying DC electrical conductivity–based ammonia vapour–sensing properties at three different ammonia concentrations, that is, 1 M, 0.5 M and 0.1 M. The PPy/MoO3 sensor showed much-improved sensing performance than the PPy sensor in terms of % sensing response and reversibility. PPy/MoO3 sensor showed excellent selectivity for ammonia vapours against various VOCs. The % sensing response of PPy/MoO3 sensor towards ammonia was found to be 2.19, 2.50, 3.16, 3.87, 4.1, 5.15, 6.19, 6.55 and 7.77 times greater than ethanol, methanol, acetone, acetaldehyde, formaldehyde, toluene, benzene, chloroform and n-hexane, respectively. In the end, a sensing mechanism was also proposed, which is based on rapid adsorption–desorption of ammonia molecules on the PPy/MoO3 sensor’s surface.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

scholarly journals Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng
Keyword(s):  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Degradation Rate ◽  
Model Compound ◽  
Vibrating Sample Magnetometer ◽  
Simulated Sunlight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Photocatalytic Reactions ◽  
Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

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