3D ordered porous SnO2 with a controllable pore diameter for enhanced formaldehyde sensing performance

2020 ◽  
Vol 13 (07) ◽  
pp. 2051044
Author(s):  
Dan Sun ◽  
Huixiao Guo ◽  
Yu Li ◽  
Haiying Li ◽  
Xiaosong Li ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Porous Structures ◽  
Gas Sensitivity ◽  
Long Term Stability ◽  
Response Recovery ◽  
Recovery Times ◽  
Formaldehyde Sensing ◽  
Different Diameters ◽  
Ordered Porous

This paper reports the preparation of 3D ordered porous SnO2 with different diameters (103, 546, and 1030[Formula: see text]nm) by a simple template method. We find that 103[Formula: see text]nm porous SnO2 nanomaterials have the highest response (30) and fastest response/recovery time (3/10 s) for 100 ppm HCHO (formaldehyde) compared with the response and response/recovery times for 546 nm (20 and 3/17[Formula: see text]s, respectively) and 1030 nm (10 and 6/20[Formula: see text]s, respectively) porous SnO2 nanomaterials at a low working temperature (220∘C). All three sensors show good long-term stability, repeatability, and linearity. The results show that decreasing the diameter of the porous SnO2 materials effectively increased the gas sensitivity to HCHO. The increase in the gas sensitivity was attributed to the ordered porous structures, large specific surface area, and additional oxygen vacancies on the surface.

scholarly journals Designing organic solvent separation membranes: Polymers, porous structures, 2D materials, and their combinations

2021 ◽  
Author(s):  
Ameya Manoj Tandel ◽  
Wenji Guo ◽  
Kelly Bye ◽  
Liang Huang ◽  
Michele Galizia ◽  
...  
Keyword(s):  
Organic Solvent ◽  
High Selectivity ◽  
2D Materials ◽  
Porous Structures ◽  
Membrane Materials ◽  
Term Stability ◽  
Long Term Stability ◽  
Separation Membranes ◽  
Tremendous Progress

As interest for membrane-based organic solvent separation increases, membrane materials exhibiting high permeance, high selectivity, and long-term stability against solvents are sought. Membrane technology has experienced tremendous progress by integrating...

scholarly journals Synthesis of a Flower-Like g-C3N4/ZnO Hierarchical Structure with Improved CH4 Sensing Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 724 ◽  
Author(s):  
Xiaojie Li ◽  
Yanwei Li ◽  
Guang Sun ◽  
Na Luo ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Carbon Nitride ◽  
Fast Response ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Response Recovery ◽  
Calcination Method

In this paper, a hierarchical structure of graphite carbon nitride (g-C3N4) modified ZnO (g-C3N4/ZnO) was synthesized using a simple precipitation-calcination method. Through this method, g-C3N4 nanosheets with a controlled content were successfully decorated on the petals of flower-like ZnO. Various techniques were used to confirm the successful formation of the g-C3N4/ZnO hierarchical structure. The methane (CH4) sensing properties of g-C3N4/ZnO sensor were investigated. The result exhibited that after decorating ZnO with g-C3N4, the CH4 sensing performances of the fabricated sensor were remarkably improved. At the optimum operating temperature of 320 °C, the response of the sensor fabricated with CNZ-3 (the sample with an optimum content of g-C3N4) towards 1000 ppm CH4 was as high as 11.9 (Ra/Rg), which was about 2.2 times higher than that of the pure ZnO sensor (5.3). In addition, the CNZ-3 sensor also exhibited a fast response/recovery speed (15/28 s) and outstanding long-term stability. The enhancing CH4 sensing mechanism may be contributed to enlarged surface area, pore structure, and g-C3N4-ZnO n-n junction.

Vertical SnO2 nanosheet@SiC nanofibers with hierarchical architecture for high-performance gas sensors

2016 ◽  
Vol 4 (2) ◽  
pp. 295-304 ◽  
Author(s):  
Bing Wang ◽  
Yingde Wang ◽  
Yongpeng Lei ◽  
Song Xie ◽  
Nan Wu ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Sensors ◽  
High Performance ◽  
High Sensitivity ◽  
Hierarchical Architecture ◽  
Long Term Stability ◽  
Response Recovery ◽  
Sno2 Nanosheet ◽  
Excellent Reproducibility

The SnO2 NS@SiC NF sensor shows an ultrafast response/recovery rate, high sensitivity, excellent reproducibility, good sensing selectivity and outstanding long-term stability toward ethanol, even at high temperature.

scholarly journals Study of lifetime of Platinum Modified Metal Oxides Electrodes

2020 ◽  
Vol 14 (4) ◽  
pp. 1479-1488
Author(s):  
Lemeyonouin Aliou Guillaume Pohan ◽  
Ollo Kambiré ◽  
Mohamed Berté ◽  
Lassiné Ouattara
Keyword(s):  
Metal Oxides ◽  
Platinum Metal ◽  
Porous Structures ◽  
Term Stability ◽  
Long Term Stability ◽  
Physical Measurements ◽  
Platinum Coating ◽  
The One ◽  
A Current

Pt, IrO2, RuO2, Pt-IrO2 and Pt-RuO2 electrodes have been shown to be effective in their application in various fields. However, it is necessary to study their long-term stability. So, our objective is to prepare them and study their lifetime using intensiostatic measurement. Then they were prepared at 400 °C on titanium plates used as a substrate. Physical measurements (scanning electron microscopy) of these anodes revealed that their surface are rough and porous structures. Lifetime study was carried out in H2SO4 9 N and under a current density of 410 mA /cm2. The long-term stability of Pt improved when coupled to IrO2 in contrast to RuO2. From this study, the performance of the electrode was found to increase in the order: RuO2 < Pt-RuO2 < Pt < Pt-IrO2 < IrO2. For RuO2 and IrO2 pure electrodes, the deactivation would be due to the dissolution of precursors deposited on the titanium. For the Pt pure electrode, deactivation would be due to the detachment of platinum coating. The deactivation of the Pt-IrO2 and Pt-RuO2 electrode would be due, on the one hand to the platinum detachment from IrO2 or RuO2 and on the other hand to the metal oxides (IrO2 or RuO2) dissolution.Keywords: Electrodes, platinum, metal oxides, lifetime.

scholarly journals Modulating Ni/Ce Ratio in NiyCe100−yOx Electrocatalysts for Enhanced Water Oxidation

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 437
Author(s):  
Jun Yu ◽  
Qi Cao ◽  
Chen Qiu ◽  
Lei Chen ◽  
Jean-Jacques Delaunay
Keyword(s):  
Oxygen Vacancy ◽  
Water Oxidation ◽  
Oxygen Vacancies ◽  
Direct Relationship ◽  
Small Mass ◽  
Transfer Resistance ◽  
Long Term Stability ◽  
Surface Areas ◽  
Tafel Slopes

Oxygen evolution reaction (OER) is the key reaction for water splitting, which is used for hydrogen production. Oxygen vacancy engineering is an effective method to tune the OER performance, but the direct relationship between the concentration of oxygen vacancy and OER activity is not well understood. Herein, a series of NiyCe100−yOx with different concentration of oxygen vacancies were successfully synthesized. The larger concentration of oxygen vacancies in Ni75Ce25Ox and Ni50Ce50Ox result in their lower Tafel slopes, small mass-transfer resistance, and larger electrochemical surface areas of the catalysts, which account for the higher OER activities for these two catalysts. Moreover, with a fixed current density of 10 mA/cm2, the potential remains stable at 1.57 V for more than 100 h, indicating the long-term stability of the Ni75Ce25Ox catalyst.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

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