scholarly journals Synthesis, Characterization, and Hydrogen Gas Sensing of ZnO/g-C3N4 Nanocomposite

2021 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Arif Ibrahim ◽  
Uzma Bano Memon ◽  
Siddartha Prakash Duttagupta ◽  
Raman R. K. Singh ◽  
Arindam Sarkar
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Material Synthesis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Recovery Times ◽  
Response And Recovery ◽  
Gas Response

In this paper, the preparation of the ZnO/g-C3N4 nanocomposite is discussed. The synthesis of nanocomposite is performed by the direct pyrolysis of the precursor (zinc acetate hexahydrate). The material synthesis is validated by different characterization tools, such as X-ray Diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM). The SEM and TEM analysis revealed the formation of nanorods on g-C3N4 support. The gas sensing property of the ZnO/g-C3N4 was studied for various concentrations of hydrogen gas. Response and recovery times were recorded by the sensor.

A Formaldehyde Gas Sensor Based on Zinc Doped Lanthanum Ferrite

2013 ◽  
Vol 873 ◽  
pp. 304-310 ◽  
Author(s):  
Jin Zhang ◽  
Yu Min Zhang ◽  
Chang Yi Hu ◽  
Zhong Qi Zhu ◽  
Qing Ju Liu
Keyword(s):  
Gas Sensing ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Lanthanum Ferrite ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Sensing Characteristics

The gas-sensing properties of zinc doped lanthanum ferrite (Zn-LaFeO3) compounds for formaldehyde were investigated in this paper. Zn-LaFeO3 powders were prepared using sol-gel method combined with microwave chemical synthesis. The powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The formaldehyde gas-sensing characteristics for the sample were examined. The experimental results indicate that the sensor based on the sample Zn-LaFeO3 shows excellent gas-sensing properties to formaldehyde gas. At the optimal operating temperature of 250°C, the sensitivity of the sensor based on LaFe0.7Zn0.3O3 to 100ppm formaldehyde is 38, while to other test gases, the sensitivity is all lower than 20. The response and recovery times for the sample to formaldehyde gas are 100s and 100s, respectively.

scholarly journals Flame-Made Pt-Loaded TiO2Thin Films and Their Application as H2Gas Sensors

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Weerasak Chomkitichai ◽  
Hathaithip Ninsonthi ◽  
Chaikarn Liewhiran ◽  
Anurat Wisitsoraat ◽  
Saengrawee Sriwichai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Hydrogen Gas Sensors ◽  
Operating Temperatures ◽  
Xrd Patterns ◽  
Deposited Film

The hydrogen gas sensors were developed successfully using flame-made platinum-loaded titanium dioxide (Pt-loaded TiO2) nanoparticles as the sensing materials. Pt-loaded TiO2thin films were prepared by spin-coating technique onto Al2O3substrates interdigitated with Au electrodes. Structural and gas-sensing characteristics were examined by using scanning electron microscopy (SEM) and showed surface morphology of the deposited film. X-ray diffraction (XRD) patterns can be confirmed to be the anatase and rutile phases of TiO2. High-resolution transmission electron microscopy (HRTEM) showed that Pt nanoparticles deposited on larger TiO2nanoparticles. TiO2films loaded with Pt nanoparticles were used as conductometric sensors for the detection of H2. The gas sensing of H2was studied at the operating temperatures of 300, 350, and 400°C in dry air. It was found that 2.00 mol% Pt-loaded TiO2sensing films showed higher response towards H2gas than the unloaded film. In addition, the responses of Pt-loaded TiO2films at all operating temperatures were higher than that of unloaded TiO2film. The response increased and the response time decreased with increasing of H2concentrations.

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.

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 Bioactivities of Geranium wallichianum Leaf Extracts Conjugated with Zinc Oxide Nanoparticles

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Banzeer Ahsan Abbasi ◽  
Javed Iqbal ◽  
Riaz Ahmad ◽  
Layiq Zia ◽  
Sobia Kanwal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Energy Dispersive ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Leaf Extracts ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron

This study attempts to obtain and test the bioactivities of leaf extracts from a medicinal plant, Geranium wallichianum (GW), when conjugated with zinc oxide nanoparticles (ZnONPs). The integrity of leaf extract-conjugated ZnONPs (GW-ZnONPs) was confirmed using various techniques, including Ultraviolet–visible spectroscopy, X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, energy-dispersive spectra (EDS), scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The size of ZnONPs was approximately 18 nm, which was determined by TEM analysis. Additionally, the energy-dispersive spectra (EDS) revealed that NPs have zinc in its pure form. Bioactivities of GW-ZnONPs including antimicrobial potentials, cytotoxicity, antioxidative capacities, inhibition potentials against α-amylase, and protein kinases, as well as biocompatibility were intensively tested and confirmed. Altogether, the results revealed that GW-ZnONPs are non-toxic, biocompatible, and have considerable potential in biological applications.

Visible-Range Luminescence Study in Indium Oxide Nanowires

2007 ◽  
Vol 1010 ◽  
Author(s):  
Davide Calestani ◽  
Mingzheng Zha ◽  
Margherita Mazzera ◽  
Laura Lazzarini ◽  
Andrea Zappettini ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Visible Range ◽  
Silicon Substrates ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Oxide Nanowires ◽  
Fundamental Properties ◽  
Transmission Electron ◽  
Temperature Spectra

AbstractThe interest in semiconducting metal oxide nanowires for gas sensing devices is today very high. Besides common materials such as SnO2 or ZnO, also In2O3 has been obtained in this quasi-1D morphology . In the present work In2O3 nanowires have been grown by vapor transport process starting from 6N pure In. For a better knowledge of the fundamental properties and the sensing mechanism of In2O3 nanowires, the obtained samples have been investigated by different techniques, focusing mainly on the optical characterization. Their morphology and structure have been studied by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-Ray diffraction. The optical properties have been investigated as well, mainly by means of photo- (PL) and Cathodo-luminescence (CL) both applied in the UV-Visible range. A complex emission spectrum has been revealed and assigned to specific defects thanks to a deep analysis of the bands as functions of temperature (varying from 20 to 300K) and to suitable thermal treatments (in oxygen rich atmosphere at 1000°C). Moreover, the effects of electron beam irradiation have been pointed out by performing CL spectra on a single In2O3 nanowire after different irradiation times. The possible influence of the substrate has been verified by measuring low temperature spectra on In2O3 nanowires grown both on alumina and silicon substrates.

scholarly journals Synthesis of ZnO Nanowires via Hotwire Thermal Evaporation of Brass (CuZn) Assisted by Vapor Phase Transport of Methanol

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Tamil Many K. Thandavan ◽  
Siti Meriam Abdul Gani ◽  
Chiow San Wong ◽  
Roslan Md Nor
Keyword(s):  
Electron Microscopy ◽  
Vapor Phase ◽  
Thermal Evaporation ◽  
Zno Nanowires ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Vapor Phase Transport ◽  
Transmission Electron ◽  
Lattice Planes ◽  
Phase Transport

Zinc oxide (ZnO) nanowires (NWs) were synthesized using vapor phase transport (VPT) and thermal evaporation of Zn from CuZn. Time dependence of ZnO NWs growth was investigated for 5, 10, 15, 20, 25, and 30 minutes. Significant changes were observed from the field electron scanning electron microscopy (FESEM) images as well as from the X-ray diffraction (XRD) profile. The photoluminescence (PL) profile was attributed to the contribution of oxygen vacancy, zinc interstitials, and hydrogen defects in the ZnO NWs. Raman scattering results show a significant peak at 143 cm−1and possible functionalization on the wall of ZnO NWs. Growth of ZnO NWs in (0002) with an estimated distance between adjacent lattice planes 0.26 nm was determined from transmission electron microscopy (TEM) analysis.

scholarly journals Highly sensitive and selective sensing of H2S gas using precipitation and impregnation-made CuO/SnO2 thick films

2021 ◽  
Author(s):  
Pimpan Leangtanom ◽  
Anurat Wisitsoraat ◽  
Kata Jaruwongrangsee ◽  
Narong Chanlek ◽  
Adisorn Tuantranont ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Fast Response ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Content ◽  
Transmission Electron ◽  
Highly Sensitive

Abstract In this work, CuO-loaded tetragonal SnO2 nanoparticles (CuO/SnO2 NPs) were synthesized using precipitation/impregnation methods with varying Cu contents of 0–25 wt% and characterized for H2S detection. The material phase, morphology, chemical composition and specific surface area of NPs were evaluated using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller analysis. From gas-sensing data, the H2S responses of SnO2 NPs were greatly enhanced by CuO loading particularly at the optimal Cu content of 20 wt%. The 20 wt%CuO/SnO2 sensor showed an excellent response of 1.36⋅105 towards 10 ppm H2S and high H2S selectivity against H2, SO2, CH4 and C2H2 at a low optimum working temperature of 200°C. In addition, the sensor provided fast response and a low detection limit of less than 0.15 ppm. The CuO-SnO2 sensor could therefore be a potential candidate for H2S detection in environmental applications.

Thermo, Photo and Mechanoluminescence Studies of Eu3+ Doped Y4Al2O9 Phosphors

2018 ◽  
pp. 389-414
Author(s):  
Shubha Tripathi ◽  
Manish Kumar Mishra ◽  
Vikas Kumar Jain ◽  
Ratnesh Tiwari ◽  
Neha Dubey
Keyword(s):  
Electron Microscopy ◽  
Solid State Reaction Method ◽  
Electric Dipole Transition ◽  
Dipole Transition ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Tem Analysis ◽  
Europium Ion ◽  
Transmission Electron

The chapter reports synthesis and characterization of europium-doped Y4Al2O9 phosphor for display and dosimetric applications. The europium-activated Y4Al2O9 (YAM) phosphor is synthesized via solid state reaction method. Synthesized phosphors were characterized by powder x-ray diffraction (PXRD) techniques, scanning electron microscopy (SEM) technique, and transmission electron microscopy (TEM) technique. Particle size calculated from TEM analysis and crystallite size was calculated by Scherer's formula. All synthesized phosphor for different concentration of europium ion were studied by photo, thermo, and mechanoluminescence study. It is found that for photoluminescence analysis of Eu3+ doped phosphor has prominent spectra in red region and electric dipole transition (5D0 → 7F2) dominant over the magnetic dipole transition (5D0 → 7F1) due to non-centro symmetry between rare earth ions. Broad excitation spectra found for photoluminescence study.

Enhanced Gas Sensing of Tin Dioxide Based Sensor for Indoor Formaldehyde Application

2021 ◽  
Vol 16 (2) ◽  
pp. 337-342
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Shanyu Liu ◽  
Ying Wang ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
Fast Response ◽  
Sensing Material ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Formaldehyde Sensing ◽  
Gas Response

Indoor formaldehyde detection is of great important at present. Using efficient solvothermal method, nanosheet-constructed and nanorod-constructed hierarchical tin dioxide (SnO2) microspheres were successfully synthesized in this work and used for the gas sensing material for indoor formaldehyde application. The as-prepared two kinds of SnO2 gas sensing materials were applied to fabricate the gas sensors and formaldehyde gas sensing experiments were carried out. The HCHO gas sensing tests indicate that the gas response of the nanosheet-constructed SnO2 microspheres is about 1.7 times higher than that of the nanorod-constructed SnO2 microspheres. In addition, both of the two SnO2 based gas sensors show almost fast response and recovery time to HCHO gas. For the nanosheet-constructed microspheres, the response value is estimated to be 32.0 at 350 °C to 60 ppm formaldehyde gas, while the response and recovery times are 7 and 5 s, respectively. The simple and efficient preparation method and improved gas sensing properties show that the as-synthesized hierarchical SnO2 microsphere that is constructed by a large amount of nanosheets exhibits significant potential application for the indoor formaldehyde sensing.

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