scholarly journals Studies on Sensing Properties and Mechanism of CuO Nanoparticles to H2S Gas

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 774 ◽  
Author(s):  
Fang Peng ◽  
Yan Sun ◽  
Yue Lu ◽  
Weiwei Yu ◽  
Meiying Ge ◽  
...  
Keyword(s):  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Oxidation Mechanism ◽  
Recovery Process ◽  
Cuo Nanoparticles ◽  
Mechanism Analysis ◽  
X Ray ◽  
Enhanced Sensitivity ◽  
Transmission Electron

In this work, the high crystalline copper oxide (CuO) nanoparticles were fabricated by a hydrothermal method, and their structural properties were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The sensing results show that CuO nanoparticles exhibit enhanced sensitivity and good selectivity for hydrogen sulfide (H2S) gas at a low temperature. There are two working mechanisms involved in the H2S sensing based on CuO nanoparticle sensors. They are the H2S oxidation mechanism and the copper sulphide (CuS) formation mechanism, respectively. The two sensing mechanisms collectively enhance the sensor’s response in the H2S sensing process. The Cu–S bonding is stable and cannot break spontaneously at a low temperature. Therefore, the CuS formation inhibits the sensor’s recovery process. Such inhibition gradually enhances as the gas concentration increases from 0.2 ppm to 5 ppm, and it becomes weaker as the operating temperature rises from 40 °C to 250 °C. The XPS results confirmed the CuS formation phenomenon, and the micro Raman spectra demonstrated that the formation of CuS bonding and its decomposition can be effectively triggered by a thermal effect. Gas-sensing mechanism analysis supplied abundant cognition for the H2S sensing phenomena based on CuO materials.

scholarly journals Nanosized V-Ce Oxides Supported on TiO2 as a Superior Catalyst for the Selective Catalytic Reduction of NO

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 202
Author(s):  
Long Lu ◽  
Xueman Wang ◽  
Chunhua Hu ◽  
Ying Liu ◽  
Xiongbo Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Redox Capacity ◽  
Scr Of No ◽  
Temperature Programmed

Nanosized V-Ce oxides supported on TiO2 (VCT) were prepared and utilized in the low-temperature selective catalytic reduction (SCR) of NO with NH3. Compared with the other V-Ce oxides-based catalysts supported on Al2O3, ZrO2, and ZSM-5, VCT showed the best SCR activity in a low-temperature range. The NOx conversion of 90% could be achieved at 220 °C. Characterizations including X-ray diffraction (XRD), scanning election micrograph (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption with NH3 (NH3-TPD), and temperature-programmed reduction with H2 (H2-TPR) showed that V1.05Ce1/TiO2 exhibited a good dispersion of V2O5, enrichment of surface Ce3+ and chemical-absorbed oxygen, and excellent redox capacity and acidity, which resulted in the best SCR performance at low temperature.

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.

scholarly journals Highly Sensitive and Selective Sensing of H2S Gas Using Precipitation and Impregnation-Made CuO/SnO2 Thick Films

2021 ◽  
Vol 16 (1) ◽  
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

AbstractIn 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 toward 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.

Sonochemical Synthesis of Nitrogen Doped TiO2 at a Low Temperature

2011 ◽  
Vol 356-360 ◽  
pp. 403-406 ◽  
Author(s):  
Xi Kui Wang ◽  
Chen Wang ◽  
Wei Lin Guo
Keyword(s):  
Photocatalytic Activity ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Methyl Violet ◽  
Sonochemical Method ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes

A visible-light activated photocatalyst N-doped TiO2 nanocrystalline was synthesized via sonochemical method at low temperature. The N-doped anatase TiO2 nanoparticles were prapared by sonication of the solution of tetrabutyl titanium and ammonium in water and ethanol at 70 °C for 150 min. The crystalline forms and crystallite sizes of the as-prepared sample is characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-Visible absorption spectrum.The product structure was dependent upon the reaction temperature and reaction time. The photocatalytic activity of the as-prepared photocatalyst was evaluated via the photodegradation of a basic dye methyl violet. The results show that the N-doped TiO2 nanocrystalline prepared by sonication has an excellent photocatalytic activity under UV light and simulated sunlight.

scholarly journals Preparation of Quasi-MIL-101(Cr) Loaded Ceria Catalysts for the Selective Catalytic Reduction of NOx at Low Temperature

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 140 ◽  
Author(s):  
Min Lu ◽  
Haili Hou ◽  
Chuanying Wei ◽  
Xiaohui Guan ◽  
Wei Wei ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Great Influence ◽  
X Ray ◽  
Nh3 Scr ◽  
Transmission Electron ◽  
Ir Transmission ◽  
Ceria Catalysts

At present, the development of novel catalysts with high activity Selective Catalytic Reduction (SCR) reaction at the low temperature is still a challenge. In this work, the authors prepare CeO2/quasi-MIL-101 catalysts with various amounts of deposited ceria by a double-solvent method, which are characterized by X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and so on. The results show that the increase of Ce content has a great influence on the catalytic property of the catalyst. The introduction of Ce can promote the conversion between Cr3+ and Cr5+ and increase the proportion of lattice oxygen, which improves the activity of the catalyst. However, the catalyst will be peroxidized when the content of Ce is too high, resulting in the decline of the catalytic activity. This experiment indicates that CeO2/quasi-MIL-101 plays a significant role in the NH3-SCR process at the low temperature when the loading of Ce is 0.5%. This work has proved the potential of this kind of material in NH3-SCR process at the low temperature, providing help for subsequent studies.

Research on Sensitization Effect of Ceria Nanoparticles on Tin Oxide Wire-in-Tube Nanofibers

2017 ◽  
Vol 735 ◽  
pp. 175-179
Author(s):  
Ye Li Gong ◽  
Jin Jin Wu ◽  
Da Wen Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Oxygen Species ◽  
Ceria Nanoparticles ◽  
X Ray ◽  
Sensing Properties ◽  
Enhanced Sensitivity ◽  
Semiconductor Oxides ◽  
Initial Resistance ◽  
Sensitization Effect

To elaborate the effect of CeO2 nanoparticles on the sensing properties of SnO2, CeO2-functionalized SnO2 wire-in-tube nanofibers (WITN) was prepared by electrospinning and subsequently impregnating treatment. The gas sensing studies revealed that the CeO2 loaded SnO2 WITN exhibited enhanced sensitivity to ethanol compared to the pristine SnO2. With increasing amount of CeO2, the response of nanocomposites increases firstly and then decreases. And the response of nanocomposites to ethanol reach maximum when the concentration of impregnated Ce (NO3)3·6H2O is 0.03 mol·L-1. To detail the sensing mechanism, the X-ray photoelectron spectroscopy was firstly employed to detect the variation in oxygen species corresponding to different amounts of CeO2, but no obviously changes in oxygen species was detected. Subsequently, it was found that the initial resistance of CeO2@SnO2 WITN was higher than pristine SnO2, which could be beneficial to the improvement of sensing properties. More importantly, oxygen vacancy (mainly offered by CeO2 nanoparticles) was proved to be positively correlated to their gas-sensing performance. In this work, the electronic sensitization mechanism based on CeO2 loaded SnO2 was detailed, which could help for the better understanding the sensitization effect of rare earth element on semiconductor oxides.

scholarly journals Effects of Chemical State of the Pd Species on H2 Sensing Characteristics of PdOx/SnO2 Based Chemiresistive Sensors

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3131 ◽  
Author(s):  
Tianjiao Qi ◽  
Jie Sun ◽  
Xi Yang ◽  
Fanfan Yan ◽  
Ji Zuo
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Sno2 Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Response Change ◽  
Hydrogen Response ◽  
Chemical States ◽  
Sensing Characteristics

In this paper, the PdOx nanoparticles modified SnO2 are prepared using sputtering and wet chemical methods. The SnO2 nanoparticles are separately added to a concentration of 0.75% to 10% PdCl2 to obtain a PdCl2/SnO2 composite material, which is calcined for 1 to 2 h at the temperatures of 120 °C, 250 °C, 450 °C and 600 °C. The PdOx/SnO2 nanocomposite was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD) and transmission electron microscopy (TEM). Microstructural observations revealed PdOx with different chemical states attached to the surface of SnO2. Hydrogen response change tests were performed on the obtained PdOx/SnO2 gas sensing materials. The results show that the high gas sensing performance may be attributed to the contribution of the PdOx-loaded SnO2. In hydrogen, the best sensitivity response was attained at 80 °C, which is 60 times that of pristine SnO2. It clarifies the role of PdOx in the gas sensing mechanisms.

Hydrothermal synthesis, characterization and gas sensing of Bi2MoxW1−xO6

2020 ◽  
Vol 13 (06) ◽  
pp. 2051032
Author(s):  
Li Zhang ◽  
Chengwen Song ◽  
Xiaoxing Zhang ◽  
Zhemin Shi ◽  
Jingkun Xiao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Good Sensitivity ◽  
Good Property ◽  
X Ray ◽  
Transmission Electron ◽  
One Step ◽  
Sensing Application

Bi2MoxW[Formula: see text]O6 microspheres are synthesized by simple one-step hydrothermal method and the morphological characterizations are performed by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The gas sensing of Bi2WO6, Bi2MoO6 and Bi2MoxW[Formula: see text]O6 is investigated. It can be concluded that the sensor of Bi2MoxW[Formula: see text]O6 has the same good sensitivity as pure Bi2MoO6 and Bi2WO6 to alcohol. It is noteworthy that the operating temperature of Bi2Mo[Formula: see text]W[Formula: see text]O6 is 200∘C which is lower than that of pure Bi2WO6 or Bi2MoO6 (240∘C), so Bi2MoxW[Formula: see text]O6 show its good property for alcohol gas sensing application.

Preparation of In2O3/MWCNTs Nanocomposites and their Gas-Sensing Property to Ethanol

2013 ◽  
Vol 562-565 ◽  
pp. 543-548 ◽  
Author(s):  
Li Zhang ◽  
Fu Bo Gu ◽  
Zhi Hua Wang ◽  
Dong Mei Han ◽  
Guang Sheng Guo
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotube ◽  
Direct Growth ◽  
Functionalized Mwcnts ◽  
Scanning Electron

In2O3/multi-walled carbon nanotube (MWCNT) nanocomposites containing different MWCNT contents were synthesized via direct growth of In2O3 nanoparticles on the functionalized MWCNTs. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results exhibited that In2O3 nanoparticles with a diameter of approximate 10 nm were densely decorated on the surface of the MWCNTs. The gas sensitive performance of the nanocomposites to ethanol was also investigated. It was found that In2O3/MWCNTs sensor showed much higher response than that of the pure In2O3 sensor. Moreover, the sensing mechanism was discussed.

scholarly journals Gas Sensing Properties of Perovskite Decorated Graphene at Room Temperature

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4563 ◽  
Author(s):  
Juan Casanova-Cháfer ◽  
Rocío García-Aboal ◽  
Pedro Atienzar ◽  
Eduard Llobet
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Gas Sensing ◽  
Semiconductor Film ◽  
Promising Alternative ◽  
Sensing Properties ◽  
Enhanced Sensitivity ◽  
Transmission Electron ◽  
Gas Sensing Properties

This paper explores the gas sensing properties of graphene nanolayers decorated with lead halide perovskite (CH3NH3PbBr3) nanocrystals to detect toxic gases such as ammonia (NH3) and nitrogen dioxide (NO2). A chemical-sensitive semiconductor film based on graphene has been achieved, being decorated with CH3NH3PbBr3 perovskite (MAPbBr3) nanocrystals (NCs) synthesized, and characterized by several techniques, such as field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Reversible responses were obtained towards NO2 and NH3 at room temperature, demonstrating an enhanced sensitivity when the graphene is decorated by MAPbBr3 NCs. Furthermore, the effect of ambient moisture was extensively studied, showing that the use of perovskite NCs in gas sensors can become a promising alternative to other gas sensitive materials, due to the protective character of graphene, resulting from its high hydrophobicity. Besides, a gas sensing mechanism is proposed to understand the effects of MAPbBr3 sensing properties.

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