Fabrication of a Highly Sensitive Single Aligned TiO₂ and Gold Nanoparticle Embedded TiO₂ Nano-Fiber Gas Sensor

Abstract

In this research, a single-aligned nanofiber of pure TiO and gold nanoparticle (GNP)-TiO were fabricated using a novel electro-spinning procedure equipped with secondary electrostatic fields on highly sharp triangular and rectangular electrodes provided for gas sensing applications. The sol used for spinning nanofiber consisted of titanium tetraisopropoxide (CHOTi), acetic acid (CHCOOH), ethanol (CHOH), polyvinylpyrrolidone (PVP), and gold nanoparticle solution. FE-SEM, TEM, and XRD were used to characterize the single nanofiber. In triangular electrodes, the electrostatic voltage for aligning single nanofiber between electrodes depends on the angle tip of the electrode, which was around 1.4-2.1, 2-2.9, and 3.2-4.1 kV for 30°, 45°, and 60°, respectively. However, by changing the shape of the electrodes to rectangular samples and by increasing distance between electrodes from 100 to 200 μm, electro-spinning applied voltage decreased. Response of pure TiO single nanofiber sensor was measured for 30-200 ppb carbon monoxide gas. The triangular sample revealed better response and lower threshold than the rectangular sample. Adding appropriate amounts of GNP decreased the operating temperature and increased the responses. CO concentration threshold for the pure TiO and GNP-TiO triangular samples was about 5 ppb and 700 ppt, respectively.

MEMS-compatible, gold nanoisland anchored 1D aligned ZnO heterojunction nanofibers: unveiling the NO2 sensing mechanism with operando photoluminescence studies

“…30 The electric field distribution on the Au IDA electrode placed between the Cu parallel plate collectors is depicted in Figure 1(d), which further confirmed that the simple parallel plate collectors can induce effective alignment of nanofibers across the IDA finger electrodes without any secondary electric field. 31,32 Based on the simulations, aligned ZnO-GNI HNFs based NO2 sensor device was fabricated by directly electrospinning using coaxial spinneret. Au sputtered IDA transducer electrode was placed between two copper parallel plate collectors to acquire appropriate alignment of nanofibers between the IDA fingers and to eliminate the ancillary potential as depicted in Figure 2(a).…”

Enhancement in the Detection Ability of Metal Oxide Sensors Using Defect‐Rich Polycrystalline Nanofiber Devices

“…To reduce AAP and HAP (CO, SO 2 ,and NO x ), semiconductor materials (ZnO, TiO 2 , and SnO 2 ) could be converted into high porosity polycrystalline nanofibers (PNFs), which have many advantages, including a nanointerface between nanograins, [ 8,9 ] wide band gap (3.6 eV), and generation‐recombination centers, owing to the defects and dangling bonds at the end of nanograin's surface. Recent studies on the development and application of PNFs suggest that they can be used in photonic devices, such as photon sensors [ 10–13 ] and solar cells, [ 14,15 ] as well as non‐photonic devices, such as PM filters, [ 16,17 ] toxic gas sensors, [ 18–34 ] biological sensors, [ 35–39 ] RRAM devices, [ 40,41 ] and energy devices. [ 42–49 ] The indoor ambient temperature for the majority of households is ≈25–30 °C.…”

Effects of Electrospinning Parameters on the Microstructure of PVP/TiO2 Nanofibers

“…These nanostructures are fabricated by the sol-gel method, hydrothermal treatment, anodic oxidation, and electrospinning [ 13 , 17 , 18 , 23 , 24 , 25 , 26 , 27 , 28 ]. With their large specific area and semiconductor properties, electrospun TiO 2 nanofibers are being researched in many fields, such as photocatalysts, solar cells, and metal oxide gas sensors [ 4 , 9 , 18 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. Electrospinning is an efficient practical technique that is low cost and has a high efficiency, and many studies have reported the production of various nanofibers [ 4 , 9 , 18 , 19 , 20 , 21 , 22 , 23 , 36 , 37 , 38 ].…”