scholarly journals Facile Fabrication of ZnO-ZnFe2O4 Hollow Nanostructure by a One-Needle Syringe Electrospinning Method for a High-Selective H2S Gas Sensor

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 399
Author(s):  
Kee-Ryung Park ◽  
Ryun Na Kim ◽  
Yoseb Song ◽  
Jinhyeong Kwon ◽  
Hyeunseok Choi
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Gas Sensing ◽  
Hollow Structure ◽  
Hollow Nanofibers ◽  
Operation Temperature ◽  
Metal Precursors ◽  
Hollow Nanostructure ◽  
H2s Gas Sensor ◽  
Facile Fabrication

Herein, a facile fabrication process of ZnO-ZnFe2O4 hollow nanofibers through one-needle syringe electrospinning and the following calcination process is presented. The various compositions of the ZnO-ZnFe2O4 nanofibers are simply created by controlling the metal precursor ratios of Zn and Fe. Moreover, the different diffusion rates of the metal oxides and metal precursors generate a hollow nanostructure during calcination. The hollow structure of the ZnO-ZnFe2O4 enables an enlarged surface area and increased gas sensing sites. In addition, the interface of ZnO and ZnFe2O4 forms a p-n junction to improve gas response and to lower operation temperature. The optimized ZnO-ZnFe2O4 has shown good H2S gas sensing properties of 84.5 (S = Ra/Rg) at 10 ppm at 250 ∘C with excellent selectivity. This study shows the good potential of p-n junction ZnO-ZnFe2O4 on H2S detection and affords a promising sensor design for a high-performance gas sensor.

scholarly journals Enhancing room-temperature NO2 gas sensing performance based on a metal phthalocyanine/graphene quantum dot hybrid material

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5618-5628
Author(s):  
Wenkai Jiang ◽  
Xinwei Chen ◽  
Tao Wang ◽  
Bolong Li ◽  
Min Zeng ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Gas Sensor ◽  
Hybrid Material ◽  
High Performance ◽  
Room Temperature ◽  
Gas Sensing ◽  
Metal Phthalocyanine ◽  
Graphene Quantum Dot ◽  
Sensing Performance

A high performance gas sensor based on a metal phthalocyanine/graphene quantum dot hybrid material was fabricated for NO2 detection at room-temperature.

Star-Fruit-Shaped CuO Structures for High Performance Ethanol Gas Sensor Device

2021 ◽  
Vol 13 (4) ◽  
pp. 724-733
Author(s):  
Ahmad Umar ◽  
Ahmed A. Ibrahim ◽  
Rajesh Kumar ◽  
Hassan Algadi ◽  
Hasan Albargi ◽  
...  
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Crystal Size ◽  
Gas Sensing ◽  
Sensor Applications ◽  
Sensor Device ◽  
Star Fruit ◽  
Micro Structures ◽  
Gas Response ◽  
Structural Crystal

In this paper, star-fruit-shaped CuO microstructures were hydrothermally synthesized and subsequently characterized through different techniques to understand morphological, compositional, structural, crystal, optical and vibrational properties. The formation of star-fruit-shaped structures along with some polygonal and spherical nanostructures was confirmed by FESEM analysis. XRD data and Raman spectrum confirmed the monoclinic tenorite crystalline phase of the CuO with crystal size 17.61 nm. Star-fruit-shaped CuO microstructures were examined for ethanol gas sensing behavior at various operating temperatures and concentrations. The gas response of 135% was observed at the optimal temperature of 225 °C. Due to excellent selectivity, stability and re-usability, the as-fabricated sensor based on star-fruit-shaped CuO micro-structures may be explored for future toxic gas sensor applications.

Two-dimensional net-like SnO2/ZnO heteronanostructures for high-performance H2S gas sensor

2016 ◽  
Vol 4 (4) ◽  
pp. 1390-1398 ◽  
Author(s):  
Diyu Fu ◽  
Chunling Zhu ◽  
Xitian Zhang ◽  
Chunyan Li ◽  
Yujin Chen
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Two Dimensional ◽  
Working Temperature ◽  
H2s Gas Sensor

Net-like SnO2/ZnO heteronanostructures with a porous feature and heterojunctions at the interfaces were successfully designed and fabricated by a facile method. Importantly, they could detect 10 ppb H2S even at a working temperature of 100 °C.

scholarly journals Nitrogen Dioxide Gas Sensor Based on Ag-Doped Graphene: A First-Principle Study

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 227
Author(s):  
Qichao Li ◽  
Yamin Liu ◽  
Di Chen ◽  
Jianmin Miao ◽  
Xiao Zhi ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
High Performance ◽  
Density Functional ◽  
Noble Metals ◽  
Gas Sensing ◽  
Mulliken Charge ◽  
Chronic Obstructive ◽  
Doped Graphene ◽  
The Impact

High-performance tracking trace amounts of NO2 with gas sensors could be helpful in protecting human health since high levels of NO2 may increase the risk of developing acute exacerbation of chronic obstructive pulmonary disease. Among various gas sensors, Graphene-based sensors have attracted broad attention due to their sensitivity, particularly with the addition of noble metals (e.g., Ag). Nevertheless, the internal mechanism of improving the gas sensing behavior through doping Ag is still unclear. Herein, the impact of Ag doping on the sensing properties of Graphene-based sensors is systematically analyzed via first principles. Based on the density-functional theory (DFT), the adsorption behavior of specific gases (NO2, NH3, H2O, CO2, CH4, and C2H6) on Ag-doped Graphene (Ag–Gr) is calculated and compared. It is found that NO2 shows the strongest interaction and largest Mulliken charge transfer to Ag–Gr among these studied gases, which may directly result in the highest sensitivity toward NO2 for the Ag–Gr-based gas sensor.

scholarly journals High Performance Acetylene Sensor with Heterostructure Based on WO3 Nanolamellae/Reduced Graphene Oxide (rGO) Nanosheets Operating at Low Temperature

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 909 ◽  
Author(s):  
Zikai Jiang ◽  
Weigen Chen ◽  
Lingfeng Jin ◽  
Fang Cui ◽  
Zihao Song ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
High Performance ◽  
Gas Sensing ◽  
Hybrid Nanocomposites ◽  
Transformer Oil ◽  
X Ray ◽  
Reduced Graphene ◽  
Sensing Performance

The development of functionalized metal oxide/reduced graphene oxide (rGO) hybrid nanocomposites concerning power equipment failure diagnosis is one of the most recent topics. In this work, WO3 nanolamellae/reduced graphene oxide (rGO) nanocomposites with different contents of GO (0.5 wt %, 1 wt %, 2 wt %, 4 wt %) were synthesized via controlled hydrothermal method. X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses-derivative thermogravimetric analysis-differential scanning calorimetry (TG-DTG-DSC), BET, and photoluminescence (PL) spectroscopy were utilized to investigate morphological characterizations of prepared gas sensing materials and indicated that high quality WO3 nanolamellae were widely distributed among graphene sheets. Experimental ceramic planar gas sensors composing of interdigitated alumina substrates, Au electrodes, and RuO2 heating layer were coated with WO3 nanolamellae/reduced graphene oxide (rGO) films by spin-coating technique and then tested for gas sensing towards multi-concentrations of acetylene (C2H2) gases in a carrier gas with operating temperature ranging from 50 °C to 400 °C. Among four contents of prepared samples, sensing materials with 1 wt % GO nanocomposite exhibited the best C2H2 sensing performance with lower optimal working temperature (150 °C), higher sensor response (15.0 toward 50 ppm), faster response-recovery time (52 s and 27 s), lower detection limitation (1.3 ppm), long-term stability, and excellent repeatability. The gas sensing mechanism for enhanced sensing performance of nanocomposite is possibly attributed to the formation of p-n heterojunction and the active interaction between WO3 nanolamellae and rGO sheets. Besides, the introduction of rGO nanosheets leads to the impurity of synthesized materials, which creates more defects and promotes larger specific area for gas adsorption, outstanding conductivity, and faster carrier transport. The superior gas sensing properties of WO3/rGO based gas sensor may contribute to the development of a high-performance ppm-level gas sensor for the online monitoring of dissolved C2H2 gas in large-scale transformer oil.

scholarly journals Incorporating N Atoms into SnO2 Nanostructure as an Approach to Enhance Gas Sensing Property for Acetone

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Gas Sensing ◽  
Diffuse Reflectance Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
X Ray ◽  
Sno2 Nanostructure

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.

scholarly journals Direct Fabrication of Reduced Graphene Oxide@SnO2 Hollow Nanofibers by Single-Capillary Electrospinning as Fast NO2 Gas Sensor

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Dong Wang ◽  
Mingcong Tang ◽  
Jianbo Sun
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Shell Structure ◽  
Composite Nanofibers ◽  
Hollow Structure ◽  
Core Shell ◽  
Hollow Nanofibers ◽  
Reduced Graphene ◽  
Core Shell Structure

Single-capillary electrospinning has been exhibited to be a simple and scalable method for fabricating nanofibers. Construction of graphene/inorganic fibers with the core-shell hollow structure using graphene as skeleton has been rarely reported. Here, we show a facile approach to prepare electrospun reduced graphene oxide@SnO2 composite nanofibers with the hollow structure. The hollow core@shell structure is formed in a single-capillary electrospinning process including sintering, which is promising for the preparation of graphene/inorganic composite nanofibers. The reduction of as-synthesized graphene is realized by stannous ion. Resulting hollow and core-shell structure enables the reduced graphene oxide@SnO2 composite nanofibers to adsorb and desorb the target gas more easily, which is promising for future applications as fast NO2 gas sensor.

scholarly journals A highly sensitive ppb-level H2S gas sensor based on fluorophenoxy-substituted phthalocyanine cobalt/rGO hybrids at room temperature

RSC Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 5993-6001
Author(s):  
Bin Wang ◽  
Xiaolin Wang ◽  
ZhiJiang Guo ◽  
Shijie Gai ◽  
Yong Li ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Gas Sensor ◽  
Room Temperature ◽  
Gas Sensing ◽  
Pollution Monitoring ◽  
Highly Sensitive ◽  
H2s Gas Sensor

Highly sensitive gas sensing materials are of great importance for environmental pollution monitoring.

UV-enhanced NO2 gas sensors based on In2O3/ZnO composite material modified by polypeptides

2021 ◽  
Author(s):  
Zhihua Ying ◽  
Teng Zhang ◽  
Chao Feng ◽  
Fei Wen ◽  
Lili Li ◽  
...  
Keyword(s):  
Composite Material ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Active Sites ◽  
High Performance ◽  
Gas Sensing ◽  
Uv Light ◽  
Gas Concentration ◽  
One Step ◽  
Strong Linear Relationship

Abstract This present study reported a high-performance gas sensor, based on In2O3/ZnO composite material modified by polypeptides, with a high sensibility to NO2, where the In2O3/ZnO composite was prepared by a one-step hydrothermal method. A series of results through material characterization technologies showed the addition of polypeptides can effectively change the morphology and size of In2O3/ZnO crystals, and effectively improve the sensing performance of the gas sensors. Due to the single shape and small size, In2O3/ZnO composite modified by polypeptides increased the active sites on the surface. At the same time, the gas sensing properties of four different ratios of polypeptide-modified In2O3/ZnO gas sensors were tested. It was found that the In2O3/ZnO-10 material showed the highest response, excellent selectivity, and good stability at room temperature under UV light. In addition, the response of the In2O3/ZnO-10 gas sensor showed a strong linear relationship with the NO2 gas concentration. When the NO2 gas concentration was 20 ppm, the response time was as quick as 19s, and the recovery time was 57s. Finally, based on the obtained experimental characterization results and energy band structure analysis, a possible gas sensing mechanism is proposed.

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