A FACILE SYNTHESIS OF FULLY POROUS TAZO COMPOSITE AND ITS REMARKABLE GAS SENSITIVE PERFORMANCE

2018 ◽  
Vol 25 (04) ◽  
pp. 1850087
Author(s):  
DONGDONG LIANG ◽  
SHIMIN LIU ◽  
ZHINUO WANG ◽  
YU GUO ◽  
WEIWEI JIANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thick Film ◽  
Cost Effective ◽  
Ethanol Vapor ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Transmission Electron ◽  
Cost Effective Method ◽  
Doped Zno ◽  
Straight Lines

The composite of a nanocrystalline SnO2 thick film deposited on an Al-doped ZnO ceramic substrate was firstly proposed. This study also provided a simple, fast and cost effective method to prepare SnO2 thick film and Al-doped ZnO ceramic as well as the final composite. The crystal structure, morphology, composition, pore size distribution and gas sensitivity of the composite were investigated by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, Barrett–Joyner–Halenda analysis and gas sensitive measurement system. Results indicated that the composite was fully porous consisted of SnO2, ZnO and ZnAl2O4 crystal phases. The macrosized pores generated in the composite could enhance the gas infiltration into the sensing layers effectively. In this way, combining a high gas-transporting-capability and a nanocrystalline SnO2 thick film, the composite showed very impressive performance. The gas sensitivity of the composite was high enough for ethanol vapor with different concentrations, which was comparable to other kinds of reported SnO2 gas sensors, while showing two straight lines with a turning point at 1000[Formula: see text]ppm. Finally, the gas sensitive mechanism was proposed based on the microstructure and composition of the composite.

scholarly journals Optimization of synthesis procedure and structure characterization of manganese tungstate nanoplates

2013 ◽  
Vol 11 (8) ◽  
pp. 1393-1401 ◽  
Author(s):  
Mehdi Rahimi-Nasrabadi ◽  
S. Pourmortazavi ◽  
Morteza Khalilian-Shalamzari ◽  
S. Hajimirsadeghi ◽  
M. Zahedi
Keyword(s):  
Electron Microscopy ◽  
Cost Effective ◽  
Structure Characterization ◽  
Precipitation Method ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Manganese Ion ◽  
Transmission Electron ◽  
Precipitation Procedure ◽  
Cost Effective Method

AbstractA simple and fast chemical method was used for synthesis of manganese tungstate nanoplates in flower-like clusters; while Taguchi robust design was employed as statistical method for optimization of the experimental parameters for the procedure. Ultrafine manganese tungstate plates in flower-like clusters were synthesized via a direct precipitation method involving addition of manganese ion solution to the aqueous tungstate reagent. Effects of various reaction conditions such as manganese and tungstate concentrations, flow rate of reagent addition and reactor temperature on the thickness of the synthesized manganese tungstate plates were investigated experimentally. Analysis of variance (ANOVA) showed that manganese tungstate nanoplates could be effectively synthesized by tuning significant parameters of precipitation procedure. Meanwhile, optimum conditions for synthesis of MnWO4 nanoplates via this simple, fast, and cost effective method were proposed. The structure and composition of the prepared nanoplates under optimum conditions were characterized by EDX, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR spectroscopy, and photoluminescence techniques.

scholarly journals Gnidia glauca- and Plumbago zeylanica-Mediated Synthesis of Novel Copper Nanoparticles as Promising Antidiabetic Agents

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dhiraj A. Jamdade ◽  
Dishantsingh Rajpali ◽  
Komal A. Joshi ◽  
Rohini Kitture ◽  
Anuja S. Kulkarni ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Copper Nanoparticles ◽  
Critical Role ◽  
Cost Effective ◽  
Significant Inhibition ◽  
Antidiabetic Activity ◽  
X Ray Diffraction ◽  
One Pot ◽  
Plumbago Zeylanica ◽  
Transmission Electron

Rapid, eco-friendly, and cost-effective one-pot synthesis of copper nanoparticles is reported here using medicinal plants like Gnidia glauca and Plumbago zeylanica. Aqueous extracts of flower, leaf, and stem of G. glauca and leaves of P. zeylanica were prepared which could effectively reduce Cu2+ ions to CuNPs within 5 h at 100°C which were further characterized using UV-visible spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, dynamic light scattering, X-ray diffraction, and Fourier-transform infrared spectroscopy. Further, the CuNPs were checked for antidiabetic activity using porcine pancreatic α-amylase and α-glucosidase inhibition followed by evaluation of mechanism using circular dichroism spectroscopy. CuNPs were found to be predominantly spherical in nature with a diameter ranging from 1 to 5 nm. The phenolics and flavonoids in the extracts might play a critical role in the synthesis and stabilization process. Significant change in the peak at ∼1095 cm−1 corresponding to C-O-C bond in ether was observed. CuNPs could inhibit porcine pancreatic α-amylase up to 30% to 50%, while they exhibited a more significant inhibition of α-glucosidase from 70% to 88%. The mechanism of enzyme inhibition was attributed due to the conformational change owing to drastic alteration of secondary structure by CuNPs. This is the first study of its kind that provides a strong scientific rationale that phytogenic CuNPs synthesized using G. glauca and P. zeylanica can be considered to develop candidate antidiabetic nanomedicine.

scholarly journals Enzyme Mimetic Activity of ZnO-Pd Nanosheets Synthesized via a Green Route

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2585 ◽  
Author(s):  
Ravi Mani Tripathi ◽  
Dohee Ahn ◽  
Yeong Mok Kim ◽  
Sang J. Chung
Keyword(s):  
Electron Microscopy ◽  
Cost Effective ◽  
Enzyme Mimics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Green Route ◽  
Protease Digestion ◽  
Recent Developments ◽  
Atomic Spacing

Recent developments in the area of nanotechnology have focused on the development of nanomaterials with catalytic activities. The enzyme mimics, nanozymes, work efficiently in extreme pH and temperature conditions, and exhibit resistance to protease digestion, in contrast to enzymes. We developed an environment-friendly, cost-effective, and facile biological method for the synthesis of ZnO-Pd nanosheets. This is the first biosynthesis of ZnO-Pd nanosheets. The synthesized nanosheets were characterized by UV–visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray. The d-spacing (inter-atomic spacing) of the palladium nanoparticles in the ZnO sheets was found to be 0.22 nm, which corresponds to the (111) plane. The XRD pattern revealed that the 2θ values of 21.8°, 33.3°, 47.7°, and 56.2° corresponded with the crystal planes of (100), (002), (112), and (201), respectively. The nanosheets were validated to possess peroxidase mimetic activity, which oxidized the 3,3′,5,5′-tetramethylbenzidine (TMB) substrate in the presence of H2O2. After 20 min of incubation time, the colorless TMB substrate oxidized into a dark-blue-colored one and a strong peak was observed at 650 nm. The initial velocities of Pd-ZnO-catalyzed TMB oxidation by H2O2 were analyzed by Michaelis–Menten and Lineweaver–Burk plots, resulting in 64 × 10−6 M, 8.72 × 10−9 Msec−1, and 8.72 × 10−4 sec−1 of KM, Vmax, and kcat, respectively.

A Facile and TGA Free Hydrothermal Synthesis of SnS Nanoparticles

NANO ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. 1750120 ◽  
Author(s):  
M. Gurubhaskar ◽  
Narayana Thota ◽  
M. Raghavender ◽  
Y. P. Venkata Subbaiah ◽  
G. Hema Chandra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Reaction Temperature ◽  
Life Time ◽  
Cost Effective ◽  
Dual Band ◽  
X Ray Diffraction ◽  
Chloride Dihydrate ◽  
Transmission Electron ◽  
Absorber Material ◽  
Vis Spectroscopy

In this paper, we employed a simple and cost-effective thioglycolic acid (TGA) free hydrothermal method, based on thiourea hydrolysis of stannous chloride dihydrate [SnCl2.2H2O] at 160[Formula: see text]C–190[Formula: see text]C for 6[Formula: see text]h, for the synthesis of SnS nanoparticles. The effect of hydrothermal autoclave reaction temperature on various properties of SnS nanoparticles have been examined at length using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy attached with EDAX (FE-SEM), transmission electron microscopy (TEM) and ultraviolet-visible (UV-Vis) spectroscopy. The results suggest that the crystallization of orthorhombic SnS nanoparticles, with size varying from 3[Formula: see text]nm to 5[Formula: see text]nm, formed at R[Formula: see text]C. Further, the formation of SnS phase was confirmed by an IR Sn-S characteristic bands around 2350[Formula: see text]cm[Formula: see text], 1041[Formula: see text]cm[Formula: see text] and 570[Formula: see text]cm[Formula: see text], and four distinguished Raman peaks at 95[Formula: see text]cm[Formula: see text], 160[Formula: see text]cm[Formula: see text], 189[Formula: see text]cm[Formula: see text] and 220[Formula: see text]cm[Formula: see text]. The mechanism for the formation of SnS nanoparticles have been proposed and discussed. The SnS nanoparticles have exhibited reaction temperature dependent morphological features like nanoflowers, nanoflakes, spherical nanoparticles and nanogranules. The absorbance studies indicated both strong direct and weak indirect allowed transitions for SnS nanoparticles and the associated band gaps were found to be 1.5[Formula: see text]eV and 1.19[Formula: see text]eV, respectively. The dual band gap combination of SnS would favor strong direct absorption of carriers and improved minority carrier life time due to indirect nature, which means the grown particles are suitable for ideal absorber material for solar cell applications.

scholarly journals Protein-assisted scalable mechanochemical exfoliation of few-layer biocompatible graphene nanosheets

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Deepak-George Thomas ◽  
Steven De-Alwis ◽  
Shalabh Gupta ◽  
Vitalij K. Pecharsky ◽  
Deyny Mendivelso-Perez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Nanosheets ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
Cytotoxic Effects ◽  
Graphene Layers ◽  
Exfoliated Graphene ◽  
Transmission Electron ◽  
Few Layer Graphene

A facile method to produce few-layer graphene (FLG) nanosheets is developed using protein-assisted mechanical exfoliation. The predominant shear forces that are generated in a planetary ball mill facilitate the exfoliation of graphene layers from graphite flakes. The process employs a commonly known protein, bovine serum albumin (BSA), which not only acts as an effective exfoliation agent but also provides stability by preventing restacking of the graphene layers. The latter is demonstrated by the excellent long-term dispersibility of exfoliated graphene in an aqueous BSA solution, which exemplifies a common biological medium. The development of such potentially scalable and toxin-free methods is critical for producing cost-effective biocompatible graphene, enabling numerous possible biomedical and biological applications. A methodical study was performed to identify the effect of time and varying concentrations of BSA towards graphene exfoliation. The fabricated product has been characterized using Raman spectroscopy, powder X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The BSA-FLG dispersion was then placed in media containing Astrocyte cells to check for cytotoxicity. It was found that lower concentrations of BSA-FLG dispersion had only minute cytotoxic effects on the Astrocyte cells.

scholarly journals Structure and gas sensitivity of WO3–In2O3 and WO3–Co3O4 oxide compositions

2019 ◽  
Vol 5 (3) ◽  
pp. 115-125 ◽  
Author(s):  
Yulyan S. Haiduk ◽  
Alexander A. Khort ◽  
Maxim A. Makhavikou ◽  
Alexander A. Savitsky
Keyword(s):  
Electron Microscopy ◽  
Nitrogen Dioxide ◽  
Sol Gel ◽  
Carbon Oxide ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Sensitivity And Selectivity ◽  
Grain Surface

Using oxide compositions is a promising method of increasing the sensitivity and selectivity of semiconductor gas sensors on the basis of SnO2, In2O3, WO3 and other oxides. We have studied nanocrystalline tungsten oxide (WO3), indium oxide (In2O3), cobalt oxide (Co3O4) and mixed oxide compositions with different WO3/In2O3 and WO3/Co3O4 ratios synthesized using the sol-gel method after xerogel annealing at 400–600 °C. The morphology, phase composition and structure of the materials have been studied using X-ray diffraction, infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. We showed that stable structures can be produced in WO3–In2O3 and WO3–Со3O4 nanoheterogeneous compositions. The growth of grain size in WO3 and In2O3, WO3 and Co3O4 during heat treatment of mixed compositions occurs slower than in simple oxides. An increase in the gas sensitivity of the compositions in comparison with simple oxides can be accounted for by smaller grain sizes and hence larger specific surface area, as well as by the dependence of grain surface state on material composition. Both compositions exhibit the greatest nitrogen dioxide response at 130–150 °C and the greatest carbon oxide response at above 230 °C. We have produced low-power nitrogen dioxide sensors with a sensitivity of << 1 ppm and power consumption of ≤ 85 mW.

Preparation of Al-doped ZnO Nanoparticulate Film for Optoelectronic Applications

2010 ◽  
Vol 1247 ◽  
Author(s):  
Thu V. Tran ◽  
Shinya Maenosono
Keyword(s):  
Electron Microscopy ◽  
Optical Transmittance ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Polar Solvents ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Optoelectronic Applications

AbstractAl-doped ZnO (AZO) nanoparticles (NPs) were synthesized by the solvothermal decomposition. The as-synthesized AZO NPs were characterized by X-ray diffraction and transmission electron microscopy. These NPs were well dispersible in non-polar solvents at high concentration to produce AZO nanoink. The AZO nanoparticulate films were prepared from AZO nanoink by spin coating technique. Thickness, surface morphology, optical transparency and conductivity of the films were characterized by surface profilometer, scanning electron microscopy, UV-Vis spectroscopy and Hall measurements. The AZO nanoparticlulate films had highly optical transmittance and well electrical conductivity, which are potential for optoelectronic applications.

Synthesis of Ultra-Fine Conducting Polyaniline Micro/Nanotubes Using Fiber Template and Their NH3 Gas Sensitivity

2007 ◽  
Vol 7 (12) ◽  
pp. 4515-4521 ◽  
Author(s):  
Bo Xue ◽  
Shaoyan Qi ◽  
Jian Gong ◽  
Yu Gao ◽  
Shuang Yao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Transmission Electron ◽  
Conducting Polyaniline ◽  
Inner Diameter ◽  
Scanning Electron

We have recently fabricated ultra-fine conducting polyaniline (PANI) tubes with high gas sensitivity. This route includes two steps. Firstly, aniline polymerizes on the surface of a suitable fiber template prepared by electrospun nitrocellulose (NC). Then, the NC fiber template is dissolved and the ultra-fine PANI tubes are obtained. The structure of the conducting PANI tubes is characterized by IR spectrum and wide-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicate that the PANI shows the shape of ultra-fine tubes with average inner diameter of 250–350 nm. The wall thickness of the ultra-fine PANI tubes increases with increasing the content of oxidant. The conductivity of the doped PANI tubes is about 6 9 × 10−2 S. The results of gas sensitivity of the ultra-fine PANI tubes indicate that the PANI tubes can act as "electronic nose" to detect toxic NH3 gas below 20 ppm.

scholarly journals Effect of Growth Temperature and Time on Morphology and Gas Sensitivity of Cu2O/Cu Microstructures

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ling Wu ◽  
Lun Zhang ◽  
Zhipeng Xun ◽  
Guili Yu ◽  
Liwei Shi
Keyword(s):  
Electron Microscopy ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Gas Response

A facile hydrothermal synthesis with CuSO4as the copper source was used to prepare micro/nano-Cu2O. The obtained samples have been characterized by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). With increasing the reaction temperature and time, the final products were successively Cu2O octahedron microcrystals, Cu2O/Cu composite particles, and a wide range of Cu spherical particles. The gas sensitivity of products towards ethanol and acetone gases was studied. The results showed that sensors prepared with Cu2O/Cu composites synthesized at 65°C for 15 min exhibited optimal gas sensitivity. The gas sensing mechanism and the effect of Cu in the enhanced gas response were also elaborated. The excellent gas sensitivity indicates that Cu2O/Cu composites have potential application as gas sensors.

Green synthesis and characterization of flower-like PbS and metal-doped nanostructures via hydrothermal method

2017 ◽  
Vol 40 (1-2) ◽  
Author(s):  
Mohsen Kord ◽  
Kambiz Hedayati ◽  
Marziyeh Farhadi
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Ultra Violet ◽  
Cost Effective ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Metal Doped ◽  
Acid Blue

AbstractIn this work, flower-like nanoparticles of lead sulfide (PbS) and metal-doped PbS nanostructures were synthesized via a simple hydrothermal method in water as a green solvent. The effect of temperature, precipitating agent and capping agent on the morphology and particle size of the products was investigated. Sugars were used as green, safe, cost-effective, and bio-compatible capping agents. The prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and ultra violet-visible spectroscopy. The effect of PbS as a photocatalyst on the degradation of three different azo dyes was investigated. Acid brown, acid violet, and acid blue were totally degraded at 60 min under ultra-violet irradiation.

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