A Novel NO₂ Sensor Applied in Natural Protected Area

Abstract

During the construction of highway, the exhaust emissions of equipment and vehicles will affect the ecological environment in a certain range around the road, especially in environmental sensitive areas such as national nature reserves, which need to be quantitatively studied. In this work, a novel two-dimensional net-like hierarchical WO3 nanostructure was synthesized by a one-step hydrothermal route. It was amazing that this novel two-dimensional WO3 show ultra-sensitivity towards NO2, primarily attributed to abundant gas diffusion channels and large gas-sensitive reaction surface area furnished by one-dimensional net-like WO3 nanowires. Benefiting from their novel characteristic, the two dimensional net-like WO3 based sensor has been applied in NO2 monitoring of the natural protected area.

α-MnO2 Nanowires as Potential Scaffolds for a High-Performance Formaldehyde Gas Sensor Device

“…In addition to the aforementioned factors, the operating temperature for a gas sensor also depends upon multiple other significant factors, such as the grain size, porosity, and surface-volume ratio of the gas sensor material. The gas diffusion rate is still another factor affecting the operating temperature [45][46][47]. Factors related to gas sensing material can be controlled by the calcination conditions during synthesis.…”

p-CuO/n-ZnO Heterojunction Structure for the Selective Detection of Hydrogen Sulphide and Sulphur Dioxide Gases: A Theoretical Approach

“…Hydrogen sulphide (H2S) and sulphur dioxide (SO2) are extremely toxic, colorless, poisonous, and dangerous gases that do not only pollute the environment but also represent a major health risk to humans [22][23][24][25]. Inhaling such gases can cause serious health issues in humans, such as eye inflammation, respiratory tract infections, asthma, cardiac damage, cancer, and irreversible pulmonary impairment, and so on [26][27][28][29][30]. As a result, an efficient technique for detecting such hazardous gases is necessary.…”

“…To explore the characteristics of both, n-and p-type semiconductor nanomaterials, MOS sensors have recently been made using p-n heterojunction nanostructures, which employ composites of p-and n-type semiconductors as functional materials to improve sensing characteristics. Thus, several p-n heterojunction nanostructure-based MOS sensors were fabricated and reported in the literature, for instance, SnO2/Co3O4, CuO/ZnO, NiO/ZnO, CuO/CuFe2O4, SnO2/CuO, WO3/CuO, and so on [22][23][24][25][26][27][28][29][30][38][39][40][41]. CuO/ZnO nanoparticles demonstrated good selectivity towards H2S gases among heterojunction nanomaterial-based MOS sensors due to the fact that the electron depletion layer on the surface of particles is enlarged by p-n heterojunctions, and the separation of electron-hole carriers increases the active sites of gas-solid reactions on the surface of the material [5][6][7][8]27].…”