scholarly journals Performances and Biosensing Mechanisms of Interdigitated Capacitive Sensors Based on the Hetero-mixture of SnO2 and In2O3

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6323
Author(s):  
Akhil Chandran Mukkattu Kuniyil ◽  
Janez Zavašnik ◽  
Željka Cvejić ◽  
Sohail Sarang ◽  
Mitar Simić ◽  
...  

This study aims to discuss the synthesis and fabrication of SnO2-In2O3-based thick-films and their biosensing applications. The structural characterization of SnO2-In2O3 nanocomposites was performed using X-ray diffraction, Raman spectroscopy and transmission electron microscopy. Furthermore, the screen-printing technology was used in the fabrication of conductive electrodes to form an interdigitated capacitive structure, and the sensor layer based on the mixture of SnO2 and In2O3. Moreover, the sensing performance of the developed structure was tested using Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) bacteria. In addition, the validation of sensing characteristics was performed by electrochemical impedance spectroscopic and self-resonant frequency analysis. Finally, the sensing properties were analyzed for two consecutive days, and changes in both P. aeruginosa and S. aureus pathogens growing media were also studied.

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Giordano T. Paganoto ◽  
Deise M. Santos ◽  
Tereza C. S. Evangelista ◽  
Marco C. C. Guimarães ◽  
Maria Tereza W. D. Carneiro ◽  
...  

This paper is consisted in the synthesis of platinum-based electrocatalysts supported on carbon (Vulcan XC-72) and investigation of the addition of gallium in their physicochemical and electrochemical properties toward ethanol oxidation reaction (EOR). PtGa/C electrocatalysts were prepared through thermal decomposition of polymeric precursor method at a temperature of 350°C. Six different compositions were homemade: Pt50Ga50/C, Pt60Ga40/C, Pt70Ga30/C, Pt80Ga20/C, Pt90Ga10/C, and Pt100/C. These electrocatalysts were electrochemically characterized by cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS) in the presence and absence of ethanol 1.0 mol L−1. Thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were also carried out for a physicochemical characterization of those materials. XRD results showed the main peaks of face-centered cubic Pt. The particle sizes obtained from XRD and TEM analysis range from 7.2 nm to 12.9 nm. The CV results indicate behavior typical of Pt-based electrocatalysts in acid medium. The CV, EIS, and CA data reveal that the addition of up to 31% of gallium to the Pt highly improves catalytic activity on EOR response when compared to Pt100/C.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.


2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).


NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  

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.


MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.


Author(s):  
Xianxue Li

Abstract Well-dispersed cerium-doped Y2SiO5 (Ce:YSO) phosphor particles with spherical morphology and good luminescence intensity have been achieved by a solvothermal method with ethanol and water as solvent media. X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectrophotometry and transmission electron microscopy were employed to characterize the as-synthesized Ce:YSO precursor and powders. The results showed that pure-phase Ce:YSO powders with a mean particle size of about 162 nm were accurately available at 310°C and above. The fluorescence ability and persistent luminescence decay properties of the Ce:YSO powders were also studied, and the excellent fluorescence properties could be attributed to the homogeneous Ce:YSO particles obtained through the solvothermal method.


2005 ◽  
Vol 3 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Jia Rong-Li ◽  
Wang Cheng-Yang ◽  
Zhu Bin

Superfine mesocarbon microbead powders (SFMCMBs) as the new supports for platinum electrocatalysts were first investigated. The Pt∕SFMCMB electrocatalysts were prepared by an impregnation-reduction method, with hexachloroplatinic acid as the platinum precursor and formaldehyde as the reducing agent. The catalysts were characterized with x-ray diffraction (XRD), field emission gun transmission electron microscope (TEM), and electrochemical analysis. TEM photos showed the platinum particles were dispersed uniformly on the surface of SFMCMBs and there existed a little aggregation of platinum particles in the Pt∕SFMCMB catalysts. The TEM photos showed the existence of the platinum on the supports where the average platinum particle size were 4-6nm. The electrochemical analysis proved that SFMCMBs are excellent candidates to be used as the support of platinum electrocatalyst for methanol electrochemical oxidation as the potential catalyst candidate for direct methanol fuel cells (DMFCs).


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