Chemiresistive NH₃ detection at sub-zero temperatures by polypyrrole- loaded Sn_1−xSb_xO₂ nanocubes

Abstract

Chemiresistive gas sensors operate mainly at high temperatures, primarily due to need of energy for surface adsorption-desorption of analytes. As a result, the operating temperature of chemiresistive sensors could be...

Ferromagnetic Ni1–xVxO1–y Nano-Clusters for NO Detection at Room Temperature: A Case of Magnetic Field-Induced Chemiresistive Sensing

“…Thick film gas sensors were fabricated using the method mentioned elsewhere . In this technique, around 0.1 g of powder sample was thoroughly mixed in iso-propyl alcohol (Merck) using mortar-pestle until a consistent slurry was formed.…”

“…Hence, all sensing experiments were further conducted for 1 ppm NO at room temperature at repeated intervals for 3 months and the sensing responses were recorded. Because NO is an oxidizing gas, sensing response ( S ) was calculated using formula S = ( R N – R NO )/ R N , where R N is the base resistance of the sensor in N 2 medium and R NO is the sensor resistance in NO medium . Because oxygen itself is paramagnetic, NO sensing experiments were performed using N 2 as the carrier gas to explicitly highlight the interaction with NO and to avoid contributions from O 2 .…”

“…Thick film gas sensors were fabricated using the method mentioned elsewhere. 57 In this technique, around 0.1 g of powder sample was thoroughly mixed in iso-propyl alcohol (Merck) using mortar-pestle until a consistent slurry was formed. Then, the slurry was casted dropwise on an enamel-coated glass epoxy-based substrate of 3 mm × 3 mm × 0.5 mm dimensions containing interdigitated tin-coated copper electrodes of gap 0.25 mm with two contacts made on alternative electrodes using conductive silver paste.…”

“…Because NO is an oxidizing gas, sensing response (S) was calculated using formula S = (R N − R NO )/R N , where R N is the base resistance of the sensor in N 2 medium and R NO is the sensor resistance in NO medium. 57 Because oxygen itself is paramagnetic, NO sensing experiments were performed using N 2 as the carrier gas to explicitly highlight the interaction with NO and to avoid contributions from O 2 . However, similar experiments were performed using NO in an air medium as well where improvement in sensing response was observed on applying an external magnetic field (see the Supporting Information); however, these results involved contribution from O 2 as well.…”

Imine Bond-Based Fluorescent Nanofilms toward High-Performance Detection and Efficient Removal of HCl and NH3

“…With acceleration of the process of industrialization, toxic but highly useful gases such as hydrogen chloride (HCl) and ammonia (NH 3 ) have been increasingly produced and used. − Due to the hazardous nature, the quantity of HCl in the air is strictly regulated in many countries as a brief exposure to 35 ppm of the gas could result in damage to the throat. In fact, the threshold for tolerably safe exposure is 10 ppm and an exposure limit of 5 ppm in the workplace is identified as hazardous .…”