Fabrication of in-situ grown and Pt-decorated ZnO nanoclusters on new-type FTO electrode for room-temperature detection of low-concentration H2S

2021 ◽  
Vol 860 ◽  
pp. 158499
Author(s):  
Jingyue Xuan ◽  
Guodong Zhao ◽  
Qianqian Gong ◽  
Lili Wang ◽  
Juanjuan Ren ◽  
...  
2020 ◽  
Vol 12 (7) ◽  
pp. 8573-8582 ◽  
Author(s):  
Guodong Zhao ◽  
Jingyue Xuan ◽  
Qianqian Gong ◽  
Lili Wang ◽  
Juanjuan Ren ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 435 ◽  
Author(s):  
Guodong Zhao ◽  
Jingyue Xuan ◽  
Xiaolin Liu ◽  
Fuchao Jia ◽  
Yuping Sun ◽  
...  

A low-cost and high-performance gas sensor was fabricated by the in-situ growing of ZnO nanoclusters (NCs) arrays on the etched fluorine-doped tin dioxide (FTO) glass via a facile dip-coating and hydrothermal method. Etched FTO glass was used as a new-type gas-sensing electrode due to its advantages of being low cost and having excellent thermal and chemical stability. ZnO NCs are composed of multiple ZnO nanorods and can provide adequate lateral contacts to constitute the paths required for the gas-sensing tests simultaneously, which can provide many advantageous point junctions for the detection of low-concentration gases. The gas-sensing tests indicate that the ZnO NCs gas sensor has good selectivity and a high response for the low-concentration H2S gas. The sensing response has reached 3.3 for 500 ppb H2S at 330 °C. The excellent gas-sensing performances should be attributed to the large specific surface area of in-situ grown ZnO NCs, the perfect ohmic contact between ZnO NCs and FTO electrode and the variation of grain boundary barrier at the cross-linked junctions of multiple nanorods. In addition, the detailed effect of work temperature and gas concentration on gas-sensing, the stability of gas sensors and the corresponding response mechanism are also discussed in the present paper.


Author(s):  
G.D. Danilatos

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.


Author(s):  
César D. Fermin ◽  
Dale Martin

Otoconia of higher vertebrates are interesting biological crystals that display the diffraction patterns of perfect crystals (e.g., calcite for birds and mammal) when intact, but fail to produce a regular crystallographic pattern when fixed. Image processing of the fixed crystal matrix, which resembles the organic templates of teeth and bone, failed to clarify a paradox of biomineralization described by Mann. Recently, we suggested that inner ear otoconia crystals contain growth plates that run in different directions, and that the arrangement of the plates may contribute to the turning angles seen at the hexagonal faces of the crystals.Using image processing algorithms described earlier, and Fourier Transform function (2FFT) of BioScan Optimas®, we evaluated the patterns in the packing of the otoconia fibrils of newly hatched chicks (Gallus domesticus) inner ears. Animals were fixed in situ by perfusion of 1% phosphotungstic acid (PTA) at room temperature through the left ventricle, after intraperitoneal Nembutal (35mg/Kg) deep anesthesia. Negatives were made with a Hitachi H-7100 TEM at 50K-400K magnifications. The negatives were then placed on a light box, where images were filtered and transferred to a 35 mm camera as described.


Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.


2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


2020 ◽  
Vol 74 (11) ◽  
pp. 866-870
Author(s):  
Lewis C. H. Maddock ◽  
Alan Kennedy ◽  
Eva Hevia

While fluoroaryl fragments are ubiquitous in many pharmaceuticals, the deprotonation of fluoroarenes using organolithium bases constitutes an important challenge in polar organometallic chemistry. This has been widely attributed to the low stability of the in situ generated aryl lithium intermediates that even at –78 °C can undergo unwanted side reactions. Herein, pairing lithium amide LiHMDS (HMDS = N{SiMe3}2) with FeII(HMDS)2 enables the selective deprotonation at room temperature of pentafluorobenzene and 1,3,5-trifluorobenzene via the mixed-metal base [(dioxane)LiFe(HMDS)3] (1) (dioxane = 1,4-dioxane). Structural elucidation of the organometallic intermediates [(dioxane)Li(HMDS)2Fe(ArF)] (ArF = C6F5, 2; 1,3,5-F3-C6H2, 3) prior electrophilic interception demonstrates that these deprotonations are actually ferrations, with Fe occupying the position previously filled by a hydrogen atom. Notwithstanding, the presence of lithium is essential for the reactions to take place as Fe II (HMDS)2 on its own is completely inert towards the metallation of these substrates. Interestingly 2 and 3 are thermally stable and they do not undergo benzyne formation via LiF elimination.


2021 ◽  
Author(s):  
Ruixue Zhang ◽  
Wanying Zhao ◽  
Zhenzhen Liu ◽  
Shanghai Wei ◽  
Yigang Yan ◽  
...  

In situ formed amorphous LiBH4·1/2NH3 on the surface of Al2O3 nanoparticles results in an enhanced ion conductivity of 1.1 × 10−3 S cm−1 at room temperature.


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