scholarly journals Catalyst-Free Vapor-Phase Method for Direct Integration of Gas Sensing Nanostructures with Polymeric Transducing Platforms

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Stella Vallejos ◽  
Isabel Gràcia ◽  
Eduardo Figueras ◽  
Carles Cané
Keyword(s):  
Tungsten Oxide ◽  
Gas Sensors ◽  
Large Scale ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Phase Method ◽  
High Concentration ◽  
Aspect Ratios

Tungsten oxide nanoneedles (NNs) are grown and integrated directly with polymeric transducing platforms for gas sensors via aerosol-assisted chemical vapor deposition (AACVD) method. Material analysis shows the feasibility to grow highly crystalline nanomaterials in the form of NNs with aspect ratios between 80 and 200 and with high concentration of oxygen vacancies at the surface, whereas gas testing demonstrates moderate sensing responses to hydrogen at concentrations between 10 ppm and 50 ppm, which are comparable with results for tungsten oxide NNs grown on silicon transducing platforms. This method is demonstrated to be an attractive route to fabricate next generation of gas sensors devices, provided with flexibility and functionality, with great potential in a cost effective production for large-scale applications.

Single-atom silver loaded on tungsten oxide with oxygen vacancies for high performance triethylamine gas sensors

2021 ◽  
Vol 9 (13) ◽  
pp. 8704-8710
Author(s):  
Jiyang Zeng ◽  
Qian Rong ◽  
Bin Xiao ◽  
Ruohan Yu ◽  
Baoye Zi ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Volatile Compounds ◽  
Gas Sensors ◽  
High Performance ◽  
Large Scale ◽  
Oxygen Vacancies ◽  
Single Atom ◽  
High Price ◽  
Sensor Materials ◽  
Low Sensitivity

Traditional sensor materials for detecting gaseous and volatile compounds still have relatively low sensitivity and high price, which limits their large-scale applications.

On the Role of Oxygen Vacancies in the Determination of the Gas-Sensing Properties of Tin-Oxide Nanowires

2006 ◽  
Vol 915 ◽  
Author(s):  
Roberto Mosca ◽  
Mingzheng Zha ◽  
Davide Calestani ◽  
Laura Lazzarini ◽  
Giancarlo Salviati ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Oxide Nanowires ◽  
Sensing Properties ◽  
Sno2 Nanowires ◽  
Gas Sensing Properties ◽  
First Results ◽  
Depth Study

AbstractSnO2 nanowires have been recently employed in the “gas-sensors” field and excellent results of conductometric and optical tests on SnO2 nanowires-based gas sensors have been reported.However, the mechanism that controls the gas-sensing effect in metal oxides nanowires is not fully understood yet. Here the authors present the first results of an in-depth study about the influence of post growth treatments on the physical and gas sensing properties of SnO2 nanowires.In particular, SnO2 nanowires grown by a vapour transport technique were annealed in a oxygen-rich atmosphere and then characterized by different techniques to assess the influence of the treatment on the nanowires properties.The annealing in oxygen atmosphere is shown to strongly affect the PL and CL spectra, the electrical resistivity as well as the gas sensing properties of the nanowires. The obtained results are consistent with a reduction of the oxygen vacancies concentration induced by the O2 treatment and seem to confirm the role of these defects in affecting the gas response of SnO2 nanowires-based sensors.

H2S Gas Sensor Based on WO3 Nanostructures Synthesized via Aerosol Assisted Chemical Vapor Deposition Technique

2019 ◽  
Vol 11 (9) ◽  
pp. 1247-1256 ◽  
Author(s):  
T. Shujah ◽  
M. Ikram ◽  
A. R. Butt ◽  
M. K. Shahzad ◽  
K. Rashid ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Sensors ◽  
Vapor Deposition ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Desorption Kinetics ◽  
Nanostructured Surfaces ◽  
Vapor Deposition Technique ◽  
H2s Gas Sensor ◽  
Adsorption Desorption

Herein we demonstrate tungsten oxide (WO3 nanostructures based resistive type sensors for hydrogen sulfide (H2S) gas sensing utility. The WO3 dynamic layers have been deposited upon alumina substrates pre-patterned with gold (Au) interdigitated electrodes. For comparative study, two distinct WO3 nanostructures (S-425 and S-450) have been synthesized using Aerosol Assisted Chemical Vapor Deposition (AACVD) technique at varied deposition temperatures i.e., 425 and 450 °C, respectively. The gas detecting properties of both sensors were investigated against varied concentration (0-60 ppm) of H2S gas levels. The electrical resistance of fabricated gas detectors has been observed at DC bias of 5 V and low operating temperature 250 °C. Specifically, when concentration of H2S gas increases from 0-10 ppm, average resistance of the S-425 and S-450 gas sensors was observed to decrease by 96.5% and 97.6%, respectively. In general, the sensing mechanism of gas sensors proposed in this work can be associated with ionosorption of oxygen species over WO3 nanostructured surfaces. However, the significantly enhanced sensing performance of S-450 sensor may be attributed to improved crystallinity in its structure and improved ions adsorption/desorption kinetics at nanorods surface morphology.

Defect-Controlled Gas Sensing Property of Nanostructured ZnO Films

2015 ◽  
Vol 814 ◽  
pp. 54-59
Author(s):  
Yong Qin Chang ◽  
Chang Jing Shao ◽  
Nan Jiang ◽  
Yan Jun Ma ◽  
Shi Qi Wang ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Zno Films ◽  
Sensor Applications ◽  
Cvd Method ◽  
Short Recovery Time ◽  
Gas Sensing Properties ◽  
Ethanol Sensing

Nanostructured ZnO films were fabricated by chemical vapor deposition (CVD) method with different Sn source concentrations for ethanol sensing application. It was found that the morphology of the ZnO films were obviously affected by Sn concentration, while no any Sn signals were detected in the films. The response of the nanostructured ZnO films increases with the increase of ethanol concentrations, and the S2 sample displays the highest sensitivity. Thephotoluminescence spectra show that more oxygen vacancies exist in the S2 sample than the other samples, which reveals that oxygen vacancies may play a great role to improve the gas sensing properties of the ZnO films.A possible sensing mechanism was proposed to explain these phenomena.This work provides a very simple and efficient method to prepare ZnO gas sensor, its high response and short recovery time are also a merit for the ZnO films used in gas sensor applications.

scholarly journals A Green and Cost-effective Approach to Reutilize the Effluent from Bleaching Process

2019 ◽  
pp. 85-90
Keyword(s):  
Large Scale ◽  
Environmental Science ◽  
Cost Effective ◽  
Synthetic Dyes ◽  
High Concentration ◽  
Cost Effective Approach ◽  
Color Yield ◽  
Wet Processing ◽  
Dyed Fabric ◽  
Textile Sector

Environmental science and management is often the most discussed subject nowadays all over the world. In a number of countries, presently plenty of harms are associated with the effluent by industrial due to growing industrialization; this issue should be considered at large scale. Textile sector is one of the leading areas, which uses a high amount of chemicals and creating environmental pollution. Textile wet processing sector uses a lot of chemicals, surfactants and synthetic dyes, hence produce a large amount of wastewater having a high concentration of chemicals. This research is an effort to investigate the amount of residue remained in liquor after bleaching and reuses this liquor by adding a few chemicals according to the requirement. Afterward, the comparison was made between the bleached sample with fresh liquor and bleached sample with reused liquor. It was observed that bleaching with reused liquor shows good results though these results are insignificantly less than fresh bleaching liquor. On the other hand, fortunately, the color yield of dyed fabric bleached with reused liquor is higher than fresh liquor.

AACVD and gas sensing properties of nickel oxide nanoparticle decorated tungsten oxide nanowires

2018 ◽  
Vol 6 (19) ◽  
pp. 5181-5192 ◽  
Author(s):  
Eric Navarrete ◽  
Carla Bittencourt ◽  
Polona Umek ◽  
Eduard Llobet
Keyword(s):  
Nickel Oxide ◽  
Tungsten Oxide ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Nickel Oxide Nanoparticles ◽  
Oxide Nanowires ◽  
Nickel Oxide Nanoparticle ◽  
Gas Sensing Properties ◽  
Oxide Nanoparticle

Here, we show that the aerosol assisted chemical vapor deposition process is suitable for growing single crystalline tungsten oxide nanowires loaded with nickel oxide nanoparticles.

scholarly journals Enhanced High-Temperature (600 °C) NO2 Response of ZnFe2O4 Nanoparticle-Based Exhaust Gas Sensors

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2133
Author(s):  
Adeel Afzal ◽  
Adnan Mujahid ◽  
Naseer Iqbal ◽  
Rahat Javaid ◽  
Umair Yaqub Qazi
Keyword(s):  
High Temperature ◽  
Gas Sensors ◽  
Oxygen Vacancies ◽  
Annealing Temperature ◽  
Gas Sensing ◽  
High Energy ◽  
Lattice Parameter ◽  
Exhaust Gas ◽  
X Ray ◽  
Znfe2o4 Nanoparticles

Fabrication of gas sensors to monitor toxic exhaust gases at high working temperatures is a challenging task due to the low sensitivity and narrow long-term stability of the devices under harsh conditions. Herein, the fabrication of a chemiresistor-type gas sensor is reported for the detection of NO2 gas at 600 °C. The sensing element consists of ZnFe2O4 nanoparticles prepared via a high-energy ball milling and annealed at different temperatures (600–1000 °C). The effects of annealing temperature on the crystal structure, morphology, and gas sensing properties of ZnFe2O4 nanoparticles are studied. A mixed spinel structure of ZnFe2O4 nanoparticles with a lattice parameter of 8.445 Å is revealed by X-ray diffraction analysis. The crystallite size and X-ray density of ZnFe2O4 nanoparticles increase with the annealing temperature, whereas the lattice parameter and volume are considerably reduced indicating lattice distortion and defects such as oxygen vacancies. ZnFe2O4 nanoparticles annealed at 1000 °C exhibit the highest sensitivity (0.13% ppm–1), sharp response (τres = 195 s), recovery (τrec = 17 s), and linear response to 100–400 ppm NO2 gas. The annealing temperature and oxygen vacancies play a major role in determining the sensitivity of devices. The plausible sensing mechanism is discussed. ZnFe2O4 nanoparticles show great potential for high-temperature exhaust gas sensing applications.

Gas Sensing Properties of Columnar CeO2 Nanostructures Prepared by Chemical Vapor Deposition

2008 ◽  
Vol 8 (2) ◽  
pp. 1012-1016 ◽  
Author(s):  
Davide Barreca ◽  
Elisabetta Comini ◽  
Alberto Gasparotto ◽  
Chiara Maccato ◽  
Cinzia Maragno ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Sensors ◽  
Vapor Deposition ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Operating Conditions ◽  
Working Temperature ◽  
Gas Sensing Properties ◽  
Resistive Gas Sensors ◽  
Higher Sensitivity

Columnar CeO2 nanostructures are grown on alumina substrates by a template- and catalyst-free Chemical Vapor Deposition (CVD) approach and subsequently tested as resistive gas sensors of CH3COCH3, H2, NO2. The sensor response is stable and reproducible throughout the whole working temperature range (200–500 °C) and directly dependent on the analyte gas and the adopted operating conditions. The higher sensitivity with respect to that displayed by continuous CeO2 thin films demonstrates the potential of fabricating nanostructured sensing devices characterized by improved functional performances.

scholarly journals A universal co-solvent dilution strategy enables facile and cost-effective fabrication of perovskite photovoltaics

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Hong Zhang ◽  
Kasra Darabi ◽  
Narges Yaghoobi Nia ◽  
Anurag Krishna ◽  
Paramvir Ahlawat ◽  
...  
Keyword(s):  
Large Scale ◽  
Perovskite Solar Cells ◽  
Precursor Solution ◽  
Cost Effective ◽  
Toxic Waste ◽  
High Concentration ◽  
Colloidal Chemistry ◽  
High Volatility ◽  
Key Issues ◽  
The Stability

AbstractCost management and toxic waste generation are two key issues that must be addressed before the commercialization of perovskite optoelectronic devices. We report a groundbreaking strategy for eco-friendly and cost-effective fabrication of highly efficient perovskite solar cells. This strategy involves the usage of a high volatility co-solvent, which dilutes perovskite precursors to a lower concentration (<0.5 M) while retaining similar film quality and device performance as a high concentration (>1.4 M) solution. More than 70% of toxic waste and material cost can be reduced. Mechanistic insights reveal ultra-rapid evaporation of the co-solvent together with beneficial alteration of the precursor colloidal chemistry upon dilution with co-solvent, which in-situ studies and theoretical simulations confirm. The co-solvent tuned precursor colloidal properties also contribute to the enhancement of the stability of precursor solution, which extends its processing window thus minimizing the waste. This strategy is universally successful across different perovskite compositions, and scales from small devices to large-scale modules using industrial spin-coating, potentially easing the lab-to-fab translation of perovskite technologies.

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