Electrospun ZnO Nanowires as Gas Sensors for Propanol Detection

2013 ◽  
Vol 562-565 ◽  
pp. 446-451 ◽  
Author(s):  
Y. Li ◽  
J.N. Ding ◽  
N.Y. Yuan
Keyword(s):  
Composite Nanofibers ◽  
Chemical Sensor ◽  
High Sensitivity ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Calcination Process ◽  
Electrospinning Method ◽  
Zno Nanofibers ◽  
Vinyl Phenol ◽  
Sensing Characteristics

We used an electrospinning method to produce ZnO nanofibers for propanol sensing. ZnO nanofibers were electrospun from a solution containing poly(4-vinyl phenol) (PVP) and zinc acetate. The morphology and structure of the as-prepared ZnO nanofibers have been characterized by scanning electron microscopy and X-ray diffraction, respectively. The calcination process of the ZnO/PVP composite nanofibers brought forth polycrystalline würtzite ZnO nanofibers with diameters of 50-70 nm. Under the optimized experimental conditions, the prepared product shows the desirable sensing characteristics towards propanol at 400°C. The high sensitivity, reversible response and good selectivity indicated its potential application as a chemical sensor.

scholarly journals Electrospun ZnSnO3/ZnO Composite Nanofibers and Its Air-Sensitive Properties

2022 ◽  
Author(s):  
Songtao Dong ◽  
Xiaoyun Jin ◽  
Junlin Wei ◽  
Hongyan Wu
Keyword(s):  
Composite Nanofibers ◽  
High Sensitivity ◽  
Fast Response ◽  
X Ray ◽  
Operational Temperature ◽  
Electrospinning Method ◽  
Sensitivity And Selectivity ◽  
Crystal Structural ◽  
Zno Nanofibers ◽  
Compositional Properties

In this work, a novel heterojunction based on ZnSnO3/ZnO nanofibers was prepared using electrospinning method. The crystal, structural and surface compositional properties of sample based on ZnSnO3 and ZnSnO3/ZnO composite nanofibers were investigated by X-ray diffractometer (XRD), Scanning electron microscope (SEM), X-ray photoelectron spectrometer (XPS) and Brunauer-Emmett-Teller (BET). Compared to pure ZnSnO3 nanofibers, the ZnSnO3/ZnO heterostructure nanofibers display high sensitivity and selectivity response with fast response towards ethanol gas at low operational temperature. The sensitivity response of sensor based on ZnSnO3/ZnO composite nanofibers were 19.6 towards 50 ppm ethanol gas at 225°C, which was about 1.5 times superior than that of pure ZnSnO3 nanofibers, which can be owed mainly to the presence of oxygen vacancies and the synergistic effect between ZnSnO3 and ZnO.

Preparation of PCL/PVP/Ag Nanofiber Membranes by Electrospinning Method

2012 ◽  
Vol 268-270 ◽  
pp. 580-583 ◽  
Author(s):  
Yong Tang Jia ◽  
Cui Wu ◽  
Feng Chun Dong ◽  
Gang Huang ◽  
Xian Hua Zeng
Keyword(s):  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Composite Nanofibers ◽  
Average Diameter ◽  
Vinyl Pyrrolidone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Nanofiber Membranes ◽  
Poly Vinyl Pyrrolidone

The composite nanofiber membranes of poly (ε-caprolactone)/poly(vinyl pyrrolidone) (PCL/PVP) containing silver nanoparticles were prepared by electrospinning method. The morphology of composite nanofibers was characterized by scanning electron microscopy (SEM). The silver nanoparticles on the electrospun fibers were characterized by X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The contact angle and water uptake of PCL/PVP/Ag nanofiber membranes were measured. The SEM photos indicated that the average diameter of the fibers was significantly decreased with the addition of silver nanoparticles. The X-Ray images showed that Ag nanoparticles were distributed on the surface of nanofiber membranes. When the PVP mole ratio was higher than 15%, the nanofiber membranes showed good hydrophilic property. The PCL/PVP/Ag nanofiber membranes could be applied to prepare wound dressing.

Methanol Sensing Properties of Electrospun SnO2 -ZnO Nanofibers

2011 ◽  
Vol 356-360 ◽  
pp. 565-568
Author(s):  
Shao Hong Wei ◽  
Mei Hua Zhou ◽  
Wei Ping Du
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Promoting Effect ◽  
Heterojunction Structure ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Electrospinning Method ◽  
Zno Nanofibers ◽  
Scanning Electron

Pure ZnO and SnO2-ZnO nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and methanol sensing properties of these fibers were investigated. The results indicate that the 20 wt% SnO2-ZnO sensor exhibits considerable sensitivity, rapid response, and good selectivity against methanol at 200 °C due to the special 1D fibers properties and the promoting effect of SnO2/ZnO heterojunction structure. The methanol sensing mechanism of SnO2-ZnO nanofibers were also discussed.

Method for synthesizing ZnO of different nanostructures by electrospinning and study of their gas sensing properties

2019 ◽  
Vol 33 (25) ◽  
pp. 1950297
Author(s):  
Xiang-Bing Li ◽  
Shu-Yi Ma ◽  
Fu-Rong Li ◽  
Yu-Xiang Zhao ◽  
Xiao-Bin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Gas Sensing Properties ◽  
Zno Nanofibers ◽  
Scanning Electron

The properties of nanomaterials usually depend on their microstructures, the same material of different microstructures could be used for various applications. However, most devices could only synthesize a single microstructure, so it is meaningful that the different microstructures were synthesized by one method. In our study, electrospinning was applied to fabricate ZnO nanofibers and nanoparticles. In this approach, Zn(Ac)/PVP composite fibers of different component ratio were synthesized by electrospinning method which was subsequently calcined and formed ZnO nanofibers and nanoparticles. The microstructure, chemical composition and gas sensing were investigated with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and WS-60A gas sensing measurement system. The synthesis mechanisms of ZnO nanofibers and nanoparticles were discussed in detail.

Fabrication and optical properties of NiO/ZnO hierarchical nanostructures

2021 ◽  
Vol 15 (1) ◽  
pp. 45-50
Author(s):  
Minh Vuong Nguyen ◽  
◽  
Ngoc Khoa Truong Nguyen ◽  
Keyword(s):  
Open Space ◽  
Visible Region ◽  
Hexagonal Structure ◽  
Nio Nanoparticles ◽  
X Ray Diffraction ◽  
Energy Dispersion Spectroscopy ◽  
Hierarchical Nanostructures ◽  
X Ray ◽  
Electrospinning Method ◽  
Zno Nanofibers

NiO/ZnO hierarchical nanostructures were synthesized by a combination of electrospinning, hydrothermal and ultraviolet (UV)-assisted deposition. Initially, ZnO nanofibers were synthesized by electrospinning method following thermal oxidation. Subsequently, ZnO hierarchical nanostructures were synthesized by hydrothermal method using ZnO nanofibers as templates. Finally, NiO nanoparticles were deposited on ZnO surface by UV-assisted deposition method. Morphology and characteristics of the material were determined by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS) and photoluminescence spectrum (PL). The results showed that the NiO/ZnO hierarchical nanostructures with high open space were obtained. NiO/ZnO crystals showed hexagonal structure of ZnO without phase formation of NiO. PL spectra of the NiO/ZnO material showed emission peaks shift towards longer wavelengths in the visible region with increasing the content of NiO nanoparticles.

Synthesis of Oriented ZnO Nanofibers Using Electrospun Method on Si (100) Substrate

2014 ◽  
Vol 1033-1034 ◽  
pp. 1094-1098
Author(s):  
Xiu Zhen Lu ◽  
Ming Tao Xu ◽  
Yan Yan Chang ◽  
Bo Peng
Keyword(s):  
Electron Microscopy ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Defect States ◽  
Calcination Process ◽  
X Ray ◽  
Growth Orientation ◽  
Transmission Electron ◽  
Zno Nanofibers ◽  
Pl Spectrum

ZnO nanofibers on Si (100) were synthesized by electrospun and calcination process. The morphology, structure and optical performance were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and photoluminescence (PL) spectrum. XRD results indicated ZnO nanofibers on Si (100) wafer calcined at 600 °C had a preferred growth orientation of (002) direction. ZnO nanofibers calcinated at 600 °C had an excellent crystalline structure with the diameters ranging from 70 to 150 nm. Defect states in the ZnO nanofibers were observed, which resulted in the green emission in PL spectrum.

scholarly journals On-chip ZnO nanofibers prepared by electrospinning method for NO2 gas detection

2018 ◽  
Vol 27 (4) ◽  
pp. 317 ◽  
Author(s):  
Van Hoang Nguyen ◽  
Van Dung Nguyen ◽  
Quang Dat Do ◽  
Thi Minh Nguyet Quan ◽  
Manh Hung Chu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
X Ray ◽  
Electrospinning Method ◽  
Resistance Modulation ◽  
Zno Nanofibers ◽  
On Chip ◽  
Gas Response

In the present study, on-chip ZnO nanofibers were fabricated by means of the electrospinning technique followed by a calcination process at 600 oC towards the gas sensor application. The morphology, composition, and crystalline structure of the as-spun and annealed ZnO nanofibers were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD), respectively. The findings show that spider-net like ZnO nanofibers with a diameter of 60 – 100 nm were successfully synthesized without any incorporation of impurities into the nanofibers. The FESEM images also reveal that each nanofiber is composed of many nanograins. The combination of experimental and calculated X-ray diffraction data indicate that ZnO nanofibers were crystallized in hexagonal wurtzite structure. For the gas sensing device application, the ZnO nanofibers-based sensors were tested with the nitrogen dioxide gas in the temperature range of 200 oC to 350 oC and concentrations from 2.5 ppm to 10 ppm. The sensing property results indicate that at the optimal working temperature of 300 oC, the ZnO nanofibers-based sensors exhibited a maximum response of 30 and 166 times on exposure of 2.5 and 10 ppm NO2 gas, respectively. The presence of nanograins within nanofibers, which results in further intensification of the resistance modulation, is responsible for such high gas response.

scholarly journals Preparation of Crystalline LaFeO3 Nanoparticles at Low Calcination Temperature: Precursor and Synthesis Parameter Effects

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5534
Author(s):  
Wen Jiang ◽  
Liwei Cheng ◽  
Jianghui Gao ◽  
Shiyu Zhang ◽  
Hao Wang ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Calcination Process ◽  
Calcination Temperatures ◽  
Lanthanum Ferrite ◽  
Lafeo3 Nanoparticles ◽  
Wet Chemical ◽  
Agglomeration Of Nanoparticles ◽  
Substantial Effort

Substantial effort has been devoted to fabricating nanocrystalline lanthanum ferrite (LaFeO3), and calcination is the crucial process of crystallization in both high-temperature strategies and wet chemical methods. Lowering the calcination temperature gives the ability to resist the growth and agglomeration of nanoparticles, therefore contributing to preserve their unique nanostructures and properties. In this work, we prepared crystalline LaFeO3 nanoparticles with a calcination process at 500 °C, lower than the calcination temperature required in most wet chemistry methods. Correspondingly, the experimental conditions, including stoichiometric ratios, pH values, precipitants, complexant regent, and the calcination temperatures, were investigated. We found that the crystalline LaFeO3 was formed with crystalline NaFeO2 after calcination at 500 °C. Furthermore, the structure of FeO6 octahedra that formed in coprecipitation was associated with the process of crystallization, which was predominantly determined by calcination temperature. Moreover, an illusion of pure-phase LaFeO3 was observed when investigated by X-ray diffraction spectroscopy, which involves amorphous sodium ferrite or potassium ferrite, respectively. These findings can help prepare nanostructured perovskite oxides at low calcination temperatures.

scholarly journals Fabrication of Electrochemical Electrodes Based on Platinum and \(\text{ZnO}\) Nanofibers for Biosensing Applications

2017 ◽  
Vol 27 (3) ◽  
pp. 221 ◽  
Author(s):  
Dang Thi Thanh Le ◽  
Nguyen Van Hoang ◽  
Nguyen Van Hieu ◽  
Vu Quang Khue ◽  
Tran Quang Huy
Keyword(s):  
Average Length ◽  
Surface Characteristics ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
X Ray ◽  
Screen Printed Electrodes ◽  
Pt Electrodes ◽  
Electrospinning Method ◽  
Zno Nanofibers ◽  
Screen Printed

Platinum (Pt) electrodes were designed in imitation of screen-printed electrodes, and prepared by microelectronic techniques. These electrodes were then modified with zinc oxide (ZnO) nanofibers for biosensing applications. ZnO nanofibers with average length \( \sim 20-30\; \mu\) m and diameter \(\sim 150\) nm in hexagonal crystalline structure are prepared using electrospinning method. Their surface characteristics were analyzed by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Electrochemical properties of modified Pt electrodes were investigated in comparison with commercial carbon screen-printed electrodes. The results showed that the cyclic voltammogram of modified Pt electrodes was stable, but has much lower resistance compared to that of carbon screen-printed electrodes.

scholarly journals Zeolite NaP1 Functionalization for the Sorption of Metal Complexes with Biodegradable N-(1,2-dicarboxyethyl)-D,L-aspartic Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus
Keyword(s):  
Experimental Data ◽  
Aspartic Acid ◽  
Ph Value ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Modified Zeolite ◽  
X Ray ◽  
Slow Release Fertilizers ◽  
Pseudo Second Order

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.

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