H₂S Gas Sensing Properties of CuO Nanotubes

Abstract

CuO nanotubes are synthesized using TeO 2 nanorod templates for application to H 2 S gas sensors. TeO 2 nanorod templates were synthesized by using the VS method through thermal evaporation. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction showed that the synthesized nanotubes were monoclinic-structured polycrystalline CuO with diameter and wall thickness of approximately 100∼300 nm and 5∼10 nm, respectively. The CuO nanotube sensor showed responses of 136∼325% for the H 2 S concentration of 0.1∼5 ppm at room temperature. These response values are approximately twice as high as that of the CuO nanowire sensor for the same concentrations of H 2 S gas.Along with the investigation of the performance of the sensors, the mechanisms of H 2 S gas sensing of the CuO nanotubes are also discussed in this study.

Graphene and g-C3N4-Based Gas Sensors

“…Sensors based on CVD made Gr show significant sensitivity to various gases at a minimum concentration of 1 ppq [90]. Schottky diode sensors made of Gr/ n-si have proven to be potential H2S gas-sensing device [91].…”

Switching Effect of p-CuO Nanotube/n-In2S3 Nanosheet Heterostructures for High-Performance Room-Temperature H2S Sensing

“…Chen et al reported that the vertically aligned CuO nanowire sensor presents almost no response to low-concentration H 2 S gas but an exceptionally high sensitivity to high-concentration H 2 S gas . However, the single-component CuO sensors usually exhibit inadequate responses to H 2 S and high operating temperature (100–300 °C), which induces high power consumption and hinders gas-sensing applications . Two-component CuO-based p–n heterostructures, such as ZnO/CuO, SnO 2 /ZnO, and SnO 2 /CuO, can adjust the electronic and chemical properties through chemical bonding and charge transfer at the interface, thus obtaining better gas-sensing performance than the single-component CuO sensors, but the working temperature is still relatively high.…”

“…12 However, the singlecomponent CuO sensors usually exhibit inadequate responses to H 2 S and high operating temperature (100−300 °C), which induces high power consumption and hinders gas-sensing applications. 13 Two-component CuO-based p−n heterostructures, such as ZnO/CuO, 14 SnO 2 /ZnO, 15 and SnO 2 /CuO, 16 can adjust the electronic and chemical properties through chemical bonding and charge transfer at the interface, thus obtaining better gas-sensing performance than the singlecomponent CuO sensors, 17 but the working temperature is still relatively high. Lots of metal sulfide-based sensors can work at room temperature and have lower power consumption, making them superior to metal−semiconductor oxide-based sensors.…”