Gas-Sensing Properties of Pt-V2O5 Thin Films for Ethanol Detection

2015 ◽  
Vol 659 ◽  
pp. 259-263 ◽  
Author(s):  
Viruntachar Kruefu ◽  
Pusit Pookmanee ◽  
Anurat Wisitsoraat ◽  
Sukon Phanichphant
Keyword(s):  
Vanadium Pentoxide ◽  
Gas Sensing ◽  
Nitrogen Adsorption ◽  
Flame Spray ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
X Ray ◽  
Transmission Electron ◽  
One Step ◽  
Ppm Level

In the present work, vanadium pentoxide (V2O5) nanoparticles have been investigated for monitoring ethanol (C2H5OH) at ppm levels in air. A one-step flame spray pyrolysis (FSP) process has been applied for the synthesis of vanadium pentoxide (V2O5) and platinum-loaded vanadium pentoxide (Pt-V2O5) nanoparticles. The samples have been studied to characterize their morphological and microstructural properties by X-ray diffraction and transmission electron microscopy. Pt addition to V2O5 samples were verified by energy dispersive X-ray spectrometry mode. The specific surface area of the nanoparticles was measured by nitrogen adsorption method. The application of the produced nanoparticles as sensitive and selective ethanol resistive sensor has been demonstrated. The Pt-loaded V2O5 sensor has shown higher response towards ethanol at ppm-level concentrations compared to unloaded one.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

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.

scholarly journals Carbon-coated titania nanostructured particles: Continuous, one-step flame-synthesis

2003 ◽  
Vol 18 (11) ◽  
pp. 2670-2676 ◽  
Author(s):  
Hendrik K. Kammler ◽  
Sotiris E. Pratsinis
Keyword(s):  
Crystal Size ◽  
Nitrogen Adsorption ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Nanostructured Particles ◽  
Carbon Particles ◽  
Transmission Electron ◽  
Carbon Coated ◽  
One Step

Concurrent synthesis of titania-carbon nanoparticles (up to 52 wt.% in C) was studied in a diffusion flame aerosol reactor by combustion of titanium tetraisopropoxide and acetylene. These graphitically layered carbon-coated titania particles were characterized by high-resolution transmission electron microscopy (HRTEM), with elemental mapping of C and Ti, x-ray diffraction (XRD), and nitrogen adsorption [Brunauer-Emmett-Teller (BET)]. The specific surface area of the powder was controlled by the acetylene flow rate from 29 to 62 m2/g as the rutile content decreased from 68 to 17 wt.%. Light blue titania suboxides formed at low acetylene flow rates. The average XRD crystal size of TiO2 decreased steadily with increasing carbon content of the composite powders, while the average BET primary particle size calculated from nitrogen adsorption decreased first and then approached a constant value. The latter is attributed to the formation of individual carbon particles next to carbon-coated titania particles as observed by HRTEM and electron spectroscopic imaging.

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

A Novel Tungsten Trioxide Based Gas Sensor for Indoor Formaldehyde Detection

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Gas Response

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.

scholarly journals A facile synthesis of a carbon-encapsulated Fe3O4 nanocomposite and its performance as anode in lithium-ion batteries

2013 ◽  
Vol 4 ◽  
pp. 699-704 ◽  
Author(s):  
Raju Prakash ◽  
Katharina Fanselau ◽  
Shuhua Ren ◽  
Tapan Kumar Mandal ◽  
Christian Kübel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lithium Ion ◽  
Iron Pentacarbonyl ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Lithium Ion Cell ◽  
Carbon Framework ◽  
One Step

A carbon-encapsulated Fe3O4 nanocomposite was prepared by a simple one-step pyrolysis of iron pentacarbonyl without using any templates, solvents or surfactants. The structure and morphology of the nanocomposite was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis and Raman spectroscopy. Fe3O4 nanoparticles are dispersed intimately in a carbon framework. The nanocomposite exhibits well constructed core–shell and nanotube structures, with Fe3O4 cores and graphitic shells/tubes. The as-synthesized material could be used directly as anode in a lithium-ion cell and demonstrated a stable capacity, and good cyclic and rate performances.

scholarly journals Hydrogen Sensor Of TiO2-Based Nanomaterials

2015 ◽  
Vol 60 (2) ◽  
pp. 935-940 ◽  
Author(s):  
B. Łysoń-Sypień ◽  
K. Zakrzewska ◽  
M. Gajewska ◽  
M. Radecka
Keyword(s):  
Gas Sensing ◽  
Hydrogen Sensor ◽  
Integrating Sphere ◽  
Flame Spray ◽  
X Ray Diffraction ◽  
Hydrogen Sensing ◽  
Transmission Electron ◽  
Optical Spectrometry ◽  
Flame Spray Synthesis ◽  
Reference Atmosphere

Abstract The aim of this research was to examine gas sensing properties of TiO2 based nanomaterials. Nanopowders of Cr doped TiO2 with constant Specific Surface Area, SSA, were obtained using Flame Spray Synthesis technique, FSS. Nanomaterials were characterized by Brunauer – Emmett – Teller adsorption isotherms, BET, X – ray diffraction, XRD, Transmission Electron Microscopy, TEM, optical spectrometry UV – vis with the use of an integrating sphere as well as impedance spectroscopy. Detection of hydrogen was carried out over the concentration range of 50 - 3000 ppm at the temperatures extending from 200 to 400°C and synthetic air working as a reference atmosphere. As a result of experiments it appeared that incorporation of 5 at.% of Cr into TiO2 improved hydrogen sensing features due to small crystallite size and predominance of rutile polymorphic phase.

Activation of persulfate by heterogeneous catalyst ZnCo2O4–RGO for efficient degradation of bisphenol A

2020 ◽  
Vol 98 (12) ◽  
pp. 771-778
Author(s):  
Xin Chang ◽  
Xiangyang Xu ◽  
Zhifeng Gao ◽  
Yingrui Tao ◽  
Yixuan Yin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bisphenol A ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
One Step ◽  
Application Potential

A nanocomposite, reduced graphene oxide (RGO) modified ZnCo2O4 (ZnCo2O4–RGO) was synthesized via one-step solvothermal method for activating persulfate (PS) to degrade bisphenol A (BPA). The morphology and structure of the nanocomposite were identified by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. RGO provides nucleation sites for ZnCo2O4 to grow and inhibits the agglomeration of the nanoparticles. The influence of different reaction conditions on the oxidation of BPA catalyzed by ZnCo2O4–RGO was investigated, including the content of RGO, the dosage of catalyst, the concentration of humic acid (HA), anions in the environment, the reaction temperature, and pH. BPA can be totally degraded within 20 min under optimized reaction conditions. The presence of HA, Cl−, and NO3− only has a slight effect on the oxidation of BPA, whereas the presence of either H2PO4− or HCO3− can greatly inhibit the reaction. ZnCo2O4–RGO shows good cycling stability and practical application potential. A reaction mechanism of the degradation of BPA was also explored.

scholarly journals Hydrothermal Synthesis of rGO/PbTiO3 Photocatalyst and Its Photocatalytic H2 Evolution Activity

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Chunyan Wang ◽  
Lianwei Shan ◽  
Dongyuan Song ◽  
Yanwei Xiao ◽  
Jagadeesh Suriyaprakash
Keyword(s):  
Photocatalytic Performance ◽  
H2 Evolution ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Efficient Charge ◽  
One Step ◽  
Photocatalytic H2 Evolution

In this letter, we investigated the photocatalytic activity of the newly formed rGO/PbTiO3 composites, which are synthesized by a one-step hydrothermal route. By adjusting the amount of reduced graphene oxide (rGO) (0, 0.15, 0.30, 0.60, and 1.20 wt%) with the PbTiO3, we constructed various photocatalysts for this investigation. The crystal structure and morphology of the various composites were studied by powder X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Photoelectron spectroscopic study revealed that the band structure of the newly formed composites and efficient charge separation can be obtained by the interfaces of various rGO content. In addition, the photocatalytic performance of the synthesized composites was explored by H2 evolution and rhodamine blue (RhB) degradation. The obtained results indicated that the addition of the appropriate amount of rGO could improve the activity of pure PbTiO3, significantly.

Facile hydrothermal synthesis of ternary CeO2–SnO2/rGO nanocomposite for supercapacitor application

2020 ◽  
Vol 13 (02) ◽  
pp. 2051005 ◽  
Author(s):  
Godlaveeti Sreenivasa Kumar ◽  
Somala Adinarayana Reddy ◽  
Hussen Maseed ◽  
Nagireddy Ramamanohar Reddy
Keyword(s):  
Electron Microscope ◽  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Energy Storage And Conversion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercapacitor Application ◽  
Transmission Electron ◽  
One Step

In this work, we present the synthesis of a ternary CeO2–SnO2/rGO nanocomposite by using a facile one-step hydrothermal method. The as-synthesized composite was structural, chemical, morphological, elemental information studied by using different characterization techniques X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDAX) and transmission electron microscope (TEM). The CeO2–SnO2/rGO exhibited an excellent specific capacitance of 156[Formula: see text]F[Formula: see text][Formula: see text] at 0.5[Formula: see text]A/g in the presence of 3 M KOH solution. The synergic effect of CeO2, SnO2 and graphene composite coated on Ni foam endowed a high specific capacitance than their individual compounds. This work suggests that the novel ternary composite is a promising candidate for the high performance electrochemical energy storage and conversion systems.

Positron Annihilation Study of Porous ZnO Synthesized with Soft Template

2017 ◽  
Vol 373 ◽  
pp. 299-302
Author(s):  
Bo Zhou ◽  
Chong Yang Li ◽  
Ning Qi ◽  
Zhi Quan Chen
Keyword(s):  
Pore Size ◽  
Positron Lifetime ◽  
Nitrogen Adsorption ◽  
Soft Template ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Long Lifetime ◽  
Positron Annihilation Study ◽  
Adsorption Desorption

Porous ZnO were synthesized with soft template method using zinc acetate Zn (CH3COO)2·2H2O as precursor and block copolymer F127 as the surfactant. Nitrogen adsorption-desorption measurements indicate that the ZnO sample contains large pores with mean diameter of about 30 nm. However, both small-angle X-ray diffraction and transmission electron microscope measurements indicate that the pore ordering is missing. Positron lifetime measurements reveal two long lifetime components in the porous ZnO. The longest lifetime τ4 (75 ns) corresponds to ortho-positronium (o-Ps) annihilation in large pores. The pore size estimated from τ4 is about 10.6 nm. This is much smaller than that estimated from Nitrogen adsorption-desorption measurements. In addition, the intensity I4 is only about 2.2%. This is probably due to the chemical quenching and/or inhibition of positronium formation induced by ZnO, which reduces o-Ps lifetime and intensity, and leads to under estimation of the pore size.

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