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In this study, ethanol detection performance of divanadium pentoxide (V2O5) nanowire array was investigated at various temperatures. The main purpose of this study is to develop a novel V2O5 nanowires-based sensor for the detection of ethanol using an Anodic Aluminum Oxide (AAO) template by direct voltage electrodeposition at room temperature. It was observed that the V2O5 nanowires were approximately 60 nm in diameter in a large area of 6 cm2. X-ray Diffraction (XRD) spectrum indicated the formation of V2O5. The XRD peak was indexed as V2O5 located at 2θ°≅ 20° that is attributed to the (001) lattice plane. The sensitivity of the V2O5 nanowire array was found 0.24 at 200 °C for 50 ppm ethanol. The results reveal that the diffusivity of the V2O5 molecules increases rapidly with increasing temperature, causing an increased sensitivity. The maximum sensor response was obtained at 200 °C. The limit of detection (LOD) of the V2O5 nanowire array sensor was 500 ppb at 200 °C. The response time (t90) of the V2O5 nanowire array sensor was calculated to be 52 s and the recovery time was 26 s at 200 °C. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the hydrogen sensing properties of nanoporous Pd–Ag and Pd–Cu alloy films based on anodic aluminum oxide (AAO) templates were investigated at various temperatures (25–100°C) and hydrogen with concentrations in the range between 250 and 5000ppm in high purity nitrogen to determine the temperature–sensitivity relationship. A hexagonally shaped AAO template of approximately 50nm in diameter and 10μm in length was fabricated as a substrate for supporting a nanoporous Pd alloy film with an approximate thickness of 80nm. The morphologies of the AAO template and the Pd alloy films were studied by scanning electron microscopy (SEM). The hydrogen sensing properties of the nanoporous Pd–Ag and Pd–Cu alloy films were measured using a transient resistance method. The sensor responses of the nanoporous Pd–Ag and Pd–Cu films on the AAO template were better than the traditional Pd–Ag and Pd–Cu thin film sensors; the sensitivities of the sensors were approximately 1.6% and 1.2%, respectively, for 1000ppm H2, and the detection limit was 250ppm at room temperature. The highest sensitivity was measured at room temperature for all alloy nanoporous sensors, and the sensitivity of the Pd–Ag nanoporous alloy was higher than that of the Pd–Cu nanoporous alloy. [Copyright &y& Elsevier]

Abstract: In this study, vertically oriented Pd0.86Fe0.14 nanowires have been fabricated using an anodized aluminum oxide (AAO) template by direct voltage electrodeposition at room temperature. AAO template-assisted electrodeposition of Pd–Fe was carried out in Pd(NH3)2Cl2:FeSO4·7H2O solution. The AAO template and the Pd0.86Fe0.14 nanowires were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) methods and X-ray diffraction (XRD). It was observed that the Pd0.86Fe0.14 nanowires were approximately 65nm in diameter and 10μm in length with an aspect ratio of 153 in a relatively large area of about 4cm2. The nucleation rate and the number of atoms in the critical nucleus are determined from the analysis of current transients. [Copyright &y& Elsevier]

In this study, vertically oriented ZnO nanowires have been fabricated using an Anodized Aluminum Oxide (AAO) template by a cathodically induced sol–gel electrodeposition method at room temperature. For fabrication of the AAO template anodization of Al was carried out in 0.3 M H2C2O4 solution under a constant voltage of 40 V. Electrodeposition of ZnO nanowires in the AAO template was carried out in aqueous Zn(NO3)2 solution. AAO template and ZnO nanowires were characterized by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). It was observed that the ZnO nanowires were approximately 70 nm in diameter and 10 μm in length with high aspect ratio. ZnO nanowires were fabricated in a relatively large area of about 5 cm2. [ABSTRACT FROM AUTHOR]

In this study, hydrogen sensing properties of nanoporous Pd films based on Anodic Aluminium Oxide (AAO) templates grown on a silicon substrate have been investigated at various temperatures (25–100°C) and hydrogen concentrations (100–1000 ppm) to determine the temperature-sensitivity relationship. For this purpose, a hexagonally shaped AAO template of approximately 50 nm in diameter and 700 nm in length with 80 nm interpore distances was fabricated using two-step anodization of an Al film deposited on an n-type (100) oriented oxidized Si substrate. Then, the nanoporous surface of the AAO template was used as a substrate for supporting a nanoporous Pd film of an approximately thickness of 60 nm. The morphologies of the AAO template and Pd film coated on the AAO template were studied mainly by Scanning Electron Microscopy (SEM). Hydrogen sensing properties of the nanoporous Pd film were measured using a resistance transient method. It was found that the sensor response of the nanoporous Pd films on the AAO template was better than the traditional Pd thin film sensors, the sensitivity of the sensor was approximately 1.8% for 1000 ppm H2, and the detection limit was lower than 100 ppm at room temperature. The highest sensitivity was measured at room temperature. [ABSTRACT FROM AUTHOR]

In this study, thin anodic aluminum oxide (AAO) templates both on silicon substrates (AAO template/SiO2/Si) and Ti-coated silicon substrates (AAO template/Ti/SiO2/Si) were developed for design of magnetic, electronic and optoelectronic devices, chemical sensors and chip-scale lithium-ion rechargeable microbatteries. Two types of AAO template were prepared by using a two-step anodization procedure. The templates were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The obtained thin AAO templates were approximately 50 nm in diameter and 700 nm in length with 80-nm interpore distances in a relatively large area of 6 cm2. A barrier layer of the AAO templates was removed by a cathodic polarization method in KCl solution for several seconds. The current–time transient during removing the alumina barrier layer of the thin AAO template and the mechanism of electrochemical dissolution of the barrier layer are given in detail. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we focused on the fabrication of two types of ZnO nanostructures, nanorods and nanowires, using different techniques. ZnO nanowires were fabricated by cathodically induced sol–gel electrodeposition using an anodic aluminum oxide (AAO) template. ZnO nanowires were approximately 65nm in diameter and 10μm in length. Also, ZnO nanorods were fabricated by a hydrothermal technique using ZnO seed layer coated glass substrate. ZnO nanorods were approximately 30nm in diameter and 1μm in length. Obtained vertical aligned ZnO nanowires and nanorods were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and UV–vis spectrophotometry. [Copyright &y& Elsevier]