This study focuses on TiO2nanorod-based gas sensor. TiO2 nanorods were fabricated on fluorine doped tin oxide (FTO) substrate by hydrothermal method. The hydrothermal solution was prepared with titanium but-oxide, hydrochloric acid and deionized water (volume ratio 1:30:30). The morphologies and structure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Highly ordered and homogenous TiO2 nanorods obtained has a diameter of ca. 100nm. Gas sensing properties of these structures were investigated against VOCs and different concentrations of H2 at 200°C. Sensor response was 200 (%) for 1000ppm H2. Among measured VOCs, TiO2 nanorods are only sensitive to isopropanol at 200°C

In this paper, we fabricated p-Co₃O₄/n-TiO₂ heterostructures and investigated their gas sensing properties. The structural and morphological characterization were performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy analysis (XPS). The electrical properties of the heterostructure were studied within the temperature range from 293 K to 423 K. Changes in electrical properties and sensing behavior against reducing and oxidizing gases were attributed to the formation of p–n heterojunctions at the Co₃O₄ and TiO₂ interface. In comparison with sensing performed with pristine TiO₂ nanotubes (NTs), a significant improvement in H₂ sensing at 200 °C was observed, while the sensing response against NO₂ decreased for the heterostructures. Additionally, a response against toluene gas, in contrast to pristine TiO₂ NTs, appeared in the Co₃O₄/TiO₂ heterostructure samples.

This letter reports, for the first time, a molybdenum-disulfide (MoS $_2$ )-coated microwave gas sensor for methanol gas detection. A wideband monopole antenna, resonating at 2.45 GHz for wireless applications, is fit with a 15-mm-long copper-based grating sensing element for high-precision gas sensing. When the sensor surface is coated with a highly sensitive layer of hydrothermally grown MoS $_2$ and exposed to methanol gas, the electrical properties of the sensing material change. The developed sensor confirms the detection of methanol gas in parts per thousand (ppt) range from 5.3 to 42.6 ppt with a sensitivity of $\sim$ 1.0 MHz/5 ppt. Furthermore, the gas-sensing functionality of the sensor does not affect the communication performances of the antenna, suggesting seamless integration into wireless sensor networks (WSNs). The simulation results, experimental data, and sensing mechanisms are provided to support the claims.

Molybdenum disulfide (MoS2), a two-dimensional transition-metal dichalcogenide, has the potential for applications in next-generation optoelectronic devices. In this work, MoS2 thin films were deposited by using radio frequency magnetron sputtering on glass and silicon substrates at different substrate temperatures. The effect of growth temperature on crystalline structure, morphology, compositional, optical, and electrical properties of MoS2 thin films was systematically evaluated. It is observed that surface morphology depended on the substrate temperature. Nanowormlike structures formed at the surface of films deposited at 100 and 200 °C. Raman analysis indicated that the mode separation distance for films deposited at room temperature was close to 25 cm−1 of the bulk value. However, mode separation was higher than 27 cm−1 when the substrate temperature was high. This can be attributed to sulfur vacancy in the MoS2 lattice and to strain formation. The bandgap of thin films was estimated to be in the range of 2.3–2.8 eV. X-ray photoelectron spectroscopy was used to investigate chemical composition as well as the effect of the substrate temperature on sulfur vacancies in films. Mo(IV)/S ratios were found to be 1.29, 1.94, and 1.87 for substrate temperatures of RT, 100 °C, and 200 °C, respectively. The conductivity of MoS2 thin films varied considerably with the substrate temperature during deposition. The highest conductivity, 10−13 S/cm, was observed at 300 K measurement temperature in films deposited at room temperature.