scholarly journals Room Temperature Detection of Acetone by a PANI/Cellulose/WO3Electrochemical Sensor

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Eider Aparicio-Martínez ◽  
Velia Osuna ◽  
Rocio B. Dominguez ◽  
Alfredo Márquez-Lucero ◽  
E. Armando Zaragoza-Contreras ◽  
...  
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
X Ray Diffraction ◽  
Acetone Concentration ◽  
Temperature Detection ◽  
Transmission Electron ◽  
Semiconducting Metal Oxides ◽  
Acetone Detection ◽  
Synthesized Materials

Chemical sensing based on semiconducting metal oxides has been largely proposed for acetone sensing, although some major technical challenges such as high operating temperature still remain unsolved. This work presents the development of an electrochemical sensor based on nanostructured PANI/cellulose/WO3composite for acetone detection at room temperature. The synthesized materials for sensor preparation were polyaniline (PANI) with a conductivity of 13.9 S/cm and tungsten trioxide (WO3) in monoclinic phase doped with cellulose as carbon source. The synthesized materials were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), cyclic voltammetry (CV), and Raman spectroscopy. The composite was applied for acetone detection in the range of 0 to 100 ppmv at room temperature with electrochemical impedance spectroscopy (EIS) for monitoring resistance changes proportional to acetone concentration. The developed sensor achieved a calculated limit of detection of 10 ppm andR2of 0.99415 with a RSD of 5% (n=3) at room temperature. According to these results, the developed sensor is suitable for acetone sensing at room temperatures without the major shortcomings of larger systems required by high operating temperatures.

scholarly journals Hydrogen Detection with SAW Polymer/Quantum Dots Sensitive Films

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4481 ◽  
Author(s):  
Izabela Constantinoiu ◽  
Cristian Viespe
Keyword(s):  
Heat Treatment ◽  
Quantum Dots ◽  
Room Temperature ◽  
Limit Of Detection ◽  
Composite Films ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Heat Treated ◽  
Gas Molecules

Regarding the use of hydrogen as a fuel, it is necessary to measure its concentration in air at room temperature. In this paper, sensitive composite films have been developed for surface acoustic wave (SAW) sensors, using quantum dots (QDs) and polymers. Si/SiO2 QDs were used due to having a high specific surface area, which considerably improves the sensitivity of the sensors compared to those that only have a polymer. Si/SiO2 QDs were obtained by laser ablation and analyzed by X-ray diffraction and transmission electron microscopy (TEM). Two types of polymers were used: polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA). Polymer and polymer with QDs compositions were deposited on the sensor substrate by drop casting. A heat treatment was performed on the films at 80 °C with a thermal dwell of two hours. The sensors obtained were tested at different hydrogen concentrations at room temperature. A limit of detection (LOD) of 452 ppm was obtained by the sensor with PDMS and Si/SiO2 QDs, which was heat treated. The results demonstrated the potential of using QDs to improve the sensitivity of the SAW sensors and to achieve a heat treatment that increases its adsorption capacity of the gas molecules.

CuWO4 Nanoparticles: Investigation of Dielectric, Electrochemical Behaviour and Photodegradation of Pharmaceutical Waste

2019 ◽  
Vol 19 (11) ◽  
pp. 7026-7034 ◽  
Author(s):  
M. Thiruppathi ◽  
M. Vahini ◽  
P. Devendran ◽  
M. Arunpandian ◽  
K. Selvakumar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Diclofenac Sodium ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Transmission Electron ◽  
Pharmaceutical Waste

The hydrothermally synthesized CuWO4 nanoparticles (NPs) were characterized with different analysis such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Energy Dispersive X-ray Spectroscopy (EDX), Cyclic Voltammetry (CV), UV-Visible and Photoluminescence (PL) analysis. The prepared CuWO4 NPs were examined with Electrochemical Impedance Spectroscopy (EIS). SEM images show that CuWO4 NPs are highly spherical shaped morphology and porous in nature. The optical band gap of prepared CuWO4 NPs is found to be 2.12 eV. Photodegradation of diclofenac sodium (DFS) (medical waste) in the aqueous medium with CuWO4 NPs under visible light irradiation shows 98% degradation. The CuWO4 NPs was stable up to 5th cycle it can be used as a reusable photocatalyst for the DFS degradation. The electrical conductivity and dielectric properties of the CuWO4 NPs at room temperature is analyzed by EIS studies. The bulk conductivity value of the prepared nanoparticles is 1.477×10-5 S/cm at room temperature. The conductivity of CuWO4 NPs is found to be due to electrons movement. The CuWO4 NPs shows higher photocatalytic and electrocatalytic activity for decomposition of DFS and methanol electro-oxidation in alkaline medium respectively.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

scholarly journals Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1141
Author(s):  
Georgia Basina ◽  
Hafsa Khurshid ◽  
Nikolaos Tzitzios ◽  
George Hadjipanayis ◽  
Vasileios Tzitzios
Keyword(s):  
Room Temperature ◽  
Colloidal Particles ◽  
Iron Pentacarbonyl ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Organometallic Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Hot Injection ◽  
The Stability

Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

Structural, Morphological, Magnetic and Self-Heating Studies of One-Step Polyol Synthesized Manganese Ferrite (MnFe2O4) Nanoparticles

2019 ◽  
Vol 19 (01) ◽  
pp. 1950003
Author(s):  
P. R. Ghutepatil ◽  
S. H. Pawar
Keyword(s):  
Room Temperature ◽  
Synthesis Method ◽  
Average Crystallite Size ◽  
Superparamagnetic Nanoparticles ◽  
Polyol Synthesis ◽  
X Ray Diffraction ◽  
Self Heating ◽  
Transmission Electron ◽  
One Step ◽  
Mnfe2o4 Nanoparticles

In this paper, uniform and superparamagnetic nanoparticles have been prepared using one-step polyol synthesis method. Structural, morphological and magnetic properties of obtained MnFe2O4 nanoparticles have been investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA) techniques. Structural investigation showed that the average crystallite size of obtained nanoparticles was about 10[Formula: see text]nm. Magnetic study revealed that the nanoparticles were superparamagnetic at room temperature with magnetization 67[Formula: see text]emu/g at room temperature. The self-heating characteristics of synthesized MnFe2O4 nanoparticles were studied by applying external AC magnetic field of 167.6 to 335.2[Formula: see text]Oe at a fixed frequency of 265[Formula: see text]kHz. The SAR values of MnFe2O4 nanoparticles were calculated for 2, 5, 10[Formula: see text]mg[Formula: see text]mL[Formula: see text] concentrations and it is observed that the threshold hyperthermia temperature is achieved for all concentrations.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

Synthesis and Photoluminescence Properties of Novel SnO2 Zigzag Nanoribbons

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ceramic Boat

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.

Preparation and Properties of Nano-Crystalline Cellulose Electro-Rheological Fluid

2015 ◽  
Vol 815 ◽  
pp. 217-221
Author(s):  
Ling Li Xu ◽  
Xing Ling Shi ◽  
Qing Liang Wang
Keyword(s):  
Room Temperature ◽  
Silicone Oil ◽  
Strong Acid ◽  
Crystalline Cellulose ◽  
Methyl Silicone ◽  
Shearing Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Crystalline ◽  
Transmission Electron

nanocrystalline cellulose (NCC) was prepared from micro-crystalline cellulose (MCC) by strong acid hydrolysis. The characteristics of such particle were studied by transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Electro-rheological fluids (ERF) were prepared by dispersing NCC and MCC in methyl-silicone oil, and their ER effects were measured. Experimental results indicated that NCC ERF exhibited a remarkable ER effect. The highest static shearing stress of NCC ERF (3.5 g/ml) was 5.1 kPa at the room temperature under a 4 .2 kV/mm electric field, increased about 5.5 times compared to MCC ERF, and sedimentation of NCC ERF was not observed even after 60 days.

New method for the production of bulk amorphous materials of Nd–Fe–B alloys

2005 ◽  
Vol 20 (3) ◽  
pp. 563-566 ◽  
Author(s):  
Tetsuji Saito ◽  
Hiroyuku Takeishi ◽  
Noboru Nakayama
Keyword(s):  
Electron Microscopy ◽  
Amorphous Materials ◽  
Room Temperature ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons

We report a new compression shearing method for the production of bulk amorphous materials. In this study, amorphous Nd–Fe–B melt-spun ribbons were successfully consolidated into bulk form at room temperature by the compression shearing method. X-ray diffraction and transmission electron microscopy studies revealed that the amorphous structure was well maintained in the bulk materials. The resultant bulk materials exhibited the same magnetic properties as the original amorphous Nd–Fe–B materials.

Corrosion protection performance of titania nanoparticles filled poly(4-methyl-5-vinylthiazole) applied on mild steel in 3.5% sodium chloride solution

2020 ◽  
pp. 875608792093930 ◽  
Author(s):  
I Pugazhenthi ◽  
S Mohammed Ghouse
Keyword(s):  
Mild Steel ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Nano Particles ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
Corrosive Media ◽  
X Ray ◽  
Polymer Hybrid ◽  
Transmission Electron

Mild steel materials have wide applications in marine construction, because they are low cost, available and easy to handle. However, they have to be protected from corrosive media by coating with polymer hybrid materials. This paper focuses on the anticorrosive properties of poly(4-methyl-5-vinylthiazole) PVTZ coatings on mild steel. Further the coating resistance is enhanced by incorporating Titania Nano particles (TiO2NPs). The nanoparticles were evaluated using X-ray diffraction studies (XRD) and transmission electron microscopy (TEM). PVTZ and its TiO2 nanocomposite were coated on mild steel. Their anticorrosive behavior was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% (w/v) NaCl.

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