Effects of Au Addition on the Performance of Thermal Electronic Noses Based on Porous CuO-SnO Nanospheres.

The electronic nose is an increasingly useful tool in many fields and applications. Our thermal electronic nose approach, based on nanostructured metal oxide chemiresistors in a thermal gradient, has the advantage of being tiny and therefore integrable in portable and wearable devices. Obviously, a wise choice of the nanomaterial is crucial for the device's performance and should therefore be carefully considered.

Impacts of Surface Modification of Pt-Sensing Electrodes with Au on Hydrogen-Sensing Properties and Mechanism of Diode-Type Gas Sensors Based on Anodized Titania.

The impacts of the surface modification of Pt-sensing electrodes with Au on the H-sensing properties and mechanism of diode-type gas sensors based on anodized titania (TiO) were discussed in this study. The sensors using Pt electrodes modified with and without Au (Au()/Pt/TiO (: sputtering time (s)) and Pt/TiO sensors, respectively) were fabricated by employing an anodized TiO film on a Ti plate. The surface modification of the Pt electrodes with Au(20) having a thickness of ca.

Effects of Gas Adsorption Properties of an Au-Loaded Porous InO Sensor on NO-Sensing Properties.

Gas adsorption properties of semiconductor-type gas sensors using porous (pr-) InO powders loaded with and without 0.5 wt % Au (Au/pr-InO and pr-InO sensors, respectively) at 100 °C were examined by using diffuse reflectance infrared Fourier transform spectroscopy, and the effect of the Au loading onto pr-InO on the NO-sensing properties were discussed in this study. We found the following: the resistance of the Au/pr-InO sensor in dry air is lower than that of the pr-InO sensor; the DRIFT spectra of both the sensors show a broad positive band between 1600 and 1000 cm in dry air (reference: in dry N at 100 °C), which mainly originates from oxygen adsorbates and/or lattice oxygen, and that this band is much larger for the Au/pr-InO sensor than for the pr-InO sensor; the Au loading also increases the adsorption amount of HO and the reactivity of NO on the pr-InO surface; and the NO response of the Au/pr-InO sensor in dry air is marginally higher than that of the pr-InO sensor in the examined concentration range of NO (0.

Synergistic Effects of PdO-CuO Loadings on Methyl Mercaptan Sensing of Porous WO Microspheres Prepared by Ultrasonic Spray Pyrolysis.

In this work, PdO-CuO co-loaded porous WO microspheres were synthesized with varying loading levels by ultrasonic spray pyrolysis (USP) using polymethyl methacrylate (PMMA) microspheres as a vehicle template. The as-prepared sensing materials and their fabricated sensor properties were characterized by X-ray analysis, nitrogen adsorption, and electron microscopy. The gas-sensing properties were studied toward methyl mercaptan (CHSH), hydrogen sulfide (HS), dimethyl sulfide (CHSCH), nitric oxide (NO), nitrogen dioxide (NO), methane (CH), ethanol (CHOH), and acetone (CHO) at 0.

Adsorption/Combustion-type Micro Gas Sensors: Typical VOC-sensing Properties and Material-design Approach for Highly Sensitive and Selective VOC Detection.

Highly sensitive and selective detection of various volatile organic compounds (VOCs) has been most needed in a wide range of fields, such as medical diagnosis, health supervision, industry-process control, and environmental monitoring. Since a semiconductor-type gas sensor is a typical promising candidate among various portable VOC-sensing devices, many efforts on developing these gas sensors are introduced in this article for the first time. Through some development stages, it has been well known that the temperature-modulated operation of gas sensors is one of effective ways to improve the magnitude of VOC responses.

Toluene-sensing Properties of Mixed-potential Type Yttria-stabilized Zirconia-based Gas Sensors Attached with Thin CeO-added Au Electrodes.

Toluene-sensing properties of mixed-potential type yttria-stabilized zirconia (YSZ)-based sensors attached with a thin CeO-added Au sensing electrode (SE, CeO content: 4 - 16 mass%, thickness: 30 - 100 nm), which was fabricated by using a spin-coating method, were examined and the effects of their SE thickness and the additive amount of CeO on their toluene response were discussed in this study. The toluene response of the sensors attached with a 16 mass% CeO-added Au SE increased with an increase in the SE thickness, and the sensor attached with the thickest 16 mass% CeO-added Au SE showed the largest response, among all the sensors tested. This behavior probably arises from the increase in the number of active sites for electrochemical toluene oxidation in the CeO-added Au SE.

Basic Gas-Sensing Properties of Photoluminescent Eu₂O₃-Mixed SnO₂-Based Materials with Submicron-Size Macropores.

Macroporous SnO₂ films mixed with 2.5 mol% Eu₂O₃ and mol% MgO (mp-Eu₂O₃/SnO₂(MgO)) were fabricated by a modified sol-gel technique employing polymethylmethacrylate microspheres (ca. 800 nm in diameter) as a template, and their photoluminescence (PL) intensities under various gaseous atmospheric conditions and gas-response behavior were investigated under the UV-light irradiation (wavelength: 260 nm) at a room temperature of ca.

Enhanced catalytic activity and thermal stability of lipase bound to oxide nanosheets.

The present study reports the effects of binding of lipase, which is an inexpensive digestive enzyme ( lipase) that catalyzes the hydrolysis reaction and is frequently utilized for artificial synthesis of a variety of organic molecules, to titanate nanosheets (TNSs) on their biocatalytic activities and stabilities under several lipase concentrations. TNSs were prepared through a hydrolysis reaction of titanium tetraisopropoxide (TTIP) with tetrabutylammonium hydroxide (TBAOH), resulting in formation of a colorless and transparent colloidal solution including TNSs with nanometric dimensions (hydrodynamic diameter: 5.6 nm).

Multicolour photochromism of colloidal solutions of niobate nanosheets intercalated with several kinds of metal ions.

Colourless and transparent colloidal solutions of niobate nanosheets intercalated with some kinds of metal ions (M-NNS, M: metal) showed quasi-reversible photochromism. Ultraviolet light irradiation of the solutions induced a change in color while maintaining the transparency, and the color change was dependent on the metal ions. The coloured solutions were bleached by exposure to an oxidizing atmosphere.

Preparation of mesoporous and/or macroporous SnO2-based powders and their gas-sensing properties as thick film sensors.

Mesoporous and/or macroporous SnO(2)-based powders have been prepared and their gas-sensing properties as thick film sensors towards H(2) and NO(2) have been investigated. The mesopores and macropores of various SnO(2)-based powders were controlled by self-assembly of sodium bis(2-ethylhexyl)sulfosuccinate and polymethyl-methacrylate (PMMA) microspheres (ca. 800 nm in diameter), respectively.

Microsphere templating as means of enhancing surface activity and gas sensitivity of CaCu(3)Ti(4)O(12) thin films.

Chemical and physical synthesis routes were combined to prepare macroporous CaCu(3)Ti(4)O(12) thin films by pulsed laser deposition onto poly(methyl methacrylate) (PMMA) microsphere templated substrates. These films showed remarkably enhanced gas sensitivity compared with control films deposited on untreated substrates, demonstrating the virtues of combining thin film physical vapor deposition (PVD) techniques in concert with colloidal templates to produce macroporous structures of inorganic films with enhanced surface activity for applications in chemical sensors, catalysts, and fuel cells.