高苑科技大學

We investigated an extended-gate field-effect transistor (EG-FET) as a pH sensor in this work. It was based on low-temperature hydrothermally grown one-dimensional (1-D) zinc oxide (ZnO) nanorod (NR) arrays. Additionally, silver nanoparticles (Ag NPs) were successfully synthesized on the surfaces of nanostructures through a simple photochemical synthesis process under ultraviolet (UV) light illumination at room temperature. The surface morphology, crystalline nature, elemental content, optical property, and electrical performance of both samples were explored and studied by field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) system, energy-dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectrometer, UV-visible spectroscopy, and a Keithley 2410 semiconductor parameter analyzer with a personal computer. FE-SEM pictures, HR-TEM patterns, and XRD results indicated that the growth of all nanostructures preferentially oriented along the c-axis resulted in hexagonal wurtzite crystals, and the 1-D NRs grew vertically on the ZnO seed layer-coated substrate. The Z@Ag-1 samples were composed of Ag (2.64 atom %), Zn (58.17 atom %), and O (39.19 atom %) in the EDX result. HR-TEM elemental mappings, EDX images, and XPS spectra demonstrated that Ag NPs existed on the surface of the 1-D ZnO NR arrays. The optical characteristics of PL analysis and UV-visible spectroscopy showed two emissions, including UV and the visible region. In the electrical section, all pH sensors showed good pH stability properties and remarkable repeatability. After Ag NP decoration, the 1-D Z@Ag-1 samples exhibited superior pH-sensing response characteristics (59.06 mV/pH, 45.65 mu A/pH) with good linearity (0.996, 0.998). Meanwhile, the hysteresis effect was only 1.49 mV as the pH of the solution changed in the following order: pH 7 -> pH 4 -> pH 7 -> pH 10 -> pH 7. The designed 1-D Z@Ag-1 pH sensors will be remarkably useful in pH-sensing fields and can be combined with Internet-of-Things applications, particularly in industrial, agricultural, medical, and military fields.

To enhance the various properties of polyvinyl alcohol (PVA), varying concentrations of carboxy-functionalized graphene (CFG) were employed in the preparation of CFG/PVA nanocomposite films. FTIR and XRD analyses revealed that CFG, in contrast to graphene, not only possesses carboxylic acid group but also exhibits higher crystallinity. Mechanical testing indicated a notable superiority of CFG addition over graphene, with optimal mechanical properties such as tensile and yield strengths being achieved at a 3% CFG concentration. Relative to pure PVA, the tensile strength and yield strength of the composite increased by 2.07 and 2.01 times, respectively. XRD analysis showed distinct changes in the crystalline structure of PVA with the addition of CFG, highlighting the influence of CFG on the composite structure. FTIR and XPS analyses confirmed the formation of ester bonds between CFG and PVA, enhancing the overall performance of the material. TGA results also demonstrated that the presence of CFG enhanced the thermal stability of CFG/PVA nanocomposite films. However, analyses using scanning electron microscopy and transmission electron microscopy revealed that a 3% concentration of CFG was uniformly dispersed, whereas a 6% concentration of CFG caused aggregation of the nanofiller, leading to a decrease in performance. The incorporation of CFG significantly enhanced the water vapor and oxygen barrier properties of PVA, with the best performance observed at a 3% CFG concentration. Beyond this concentration, barrier properties were diminished owing to CFG aggregation. The study further demonstrated an increase in electrical conductivity and hydrophobicity of the nanocomposites with the addition of CFG. Antibacterial tests against E. coli showed that CFG/PVA nanocomposites exhibited excellent antibacterial properties, especially at higher CFG concentrations. These findings indicate that CFG/PVA nanocomposites, with an optimized CFG concentration, have significant potential for applications requiring enhanced mechanical strength, barrier properties, and antibacterial capabilities.

This work explores the growth of vertically aligned zinc oxide nanorod (ZnO NR) arrays on a conductive indium-tin-oxide (ITO) substrate by using a simple hydrothermal solution route method at 95 degrees C for 3 h. Additionally, the gold nanoparticles (Au NPs) were victoriously adsorbed on the NR surface through a low-cost photochemical method under ultraviolet (UV) light at room temperature for field-emission (FE) emitters. To explore one-dimensional (1-D) nanostructures, high-resolution transmission electron microscope (HR-TEM), X-ray diffraction (XRD), and field-emission scanning electron microscope (FE-SEM) measurement were conducted. It was found that the NRs were almost perpendicular to the substrate with c-axis direction. The Au concentration of the 1-D NR array was 0.75 at% in energy-dispersive X-ray (EDX) result. ZnO nanomaterials with and without Au NPs were labelled 1-D Z@Au-3 and Z@Au-0 NRs, respectively. The turn-on electric field and effective field enhancement factor (beta) of the Z@Au-0 NR devices were 4.56 V/mu m and 4902, and those of the Z@Au-3 NR devices were 3.25 V/mu m and 12955, respectively. Meanwhile, the slope value of the Z@Au-3 sample (6.43) was also lower than that of the Z@Au-0 NR sample (17.01). It can be seen that the Au NPs enhanced the FE property of the emitter. As a result, the designed 1-D ZnO samples with noble Au NPs are an encouraging candidate in future FE-based device applications, which can use in various electronic applications such as FE display panels, X-ray sources, light sources, and parallel electron beam microscopes.

Spherical TiO2 nano- to microparticles are rapidly synthesized by spraying clear stock solution as a nano aerosol into an atmospheric-pressure microwave plasma torch at 550–600°C. The stock solution was prepared by an initial H2O/TiCl4 (titanium tetrachloride) volume ratio of 8. At about 0.15 s, anatase TiO2 powders were produced and collected by 14-stage impactors. The size distribution shows that 98.47

In this work, yttrium-doped zinc oxide (Y-doped ZnO) nanorod (NR) arrays were grown using a simple facile hydrothermal solution route at low temperature to fabricate a self-powered gas sensor based on piezoelectric nanogenerator (PENG). The material properties of the one-dimensional (1-D) NR arrays were observed using a field-emission scanning electron microscopy (FE-SEM) with an energy-dispersive X-ray (EDX), an X-ray diffraction (XRD), and a high-resolution transmission electron microscope (HR-TEM). The Y-doping concentration in the ZnO NRs was estimated to be 0.96 at%. Photoluminescence (PL) analysis was used to analyze the distribution of oxygen defects in the nanostructures. The Y-doped ZnO NRs were grown onto the bottom substrate and indium-tin-oxide polyethylene terephthalate (ITO-PET) substrates with silver (Ag) electrode were used as the top electrode to fabricate the PENG device. By introducing regular frequency mechanical external forces through a home-made impact system, the ZnO NRs of PENG devices generate piezoelectric effects, then the output electrical characteristics of PENGs were measured. It can be seen that the NRs with a Y-doping concentration of 7.5 mM showed a significant change in output voltage and current when exposed to carbon monoxide (CO) gas. Meanwhile, the Y:ZnO PENGs revealed remarkable sensitivity (58%) in 150 ppm CO environment. As a result, it was seen that such a device exhibited a self-powering characteristic and a significant sensitivity to CO gas. In the future, the device can also be combined with the Internet of things (IoTs) for CO gas detection (e.g., portable gas sensors).