A panoramic view of NOx and NH3 gas sensors

Perspectives of 2D MXene-based materials for self-powered smart gas sensors

“…The discovery of graphene, a 2D material with exceptional electronic properties, ignited interest in exploring other 2D materials, leading to the discovery of MXenes. 1–3 MXenes, a family of 2D transition metal carbides and nitrides, have attracted attention due to their high surface area, tunable electronic properties, and facile surface functionalization. The current state of the art reflects a surge in the number of publications, with a rough estimate of several hundred papers dedicated to exploring the potential of 2D MXenes in gas sensing.…”

Preparation and NH3 gas-sensing properties of Ag/β-AgVO3 nanorods

“…Numerous studies have explored using metal oxide semiconductors (MOSs) for NH 3 gas sensing. 2–9 MOS materials like SnO 2 , TiO 2 , WO 3 , and ZnO are commonly utilized for NH 3 gas-sensing because of their favourable characteristics, such as ease of synthesis and cost-effectiveness. However, these sensors typically operate within temperature ranges of 250 to 550 °C.…”

“…Nanostructured materials based on metal oxide semiconductors (MOSs) have been widely synthesized for enhancing the response and lowering the working temperature of NH 3 gas sensors, owing to their large specific surface areas and high surface reactivity. 9,16–23 Recently, one-dimensional (1D) nanostructured MOSs, including nanowires (NWs), nanotubes (NTs), nanobelts (NBs), and nanorods (NRs), have been widely investigated as NH 3 gas-sensing materials due to their unique characteristics, such as numerous unsaturated chemical bonds, high length-to-diameter ratios, and rapid charge carrier transport. 21,24–27 Furthermore, the integration of noble metal nanoparticles such as Au, Pd, Pt, and Ag onto MOS surfaces has been explored extensively to significantly enhance NH 3 gas-sensing sensitivity.…”

Films of substituted zinc phthalocyanines as active layers of chemiresistive sensors for ammonia detection

“…The threshold limit value set by the Occupational Safety and Health Administration (OSHA) in the workplace is 50 ppm. 33 For the use of ammonia sensors for medical purposes, in particular for the analysis of exhaled air, sensors with a detection limit of less than 2 ppm are required. 34 In this regard, the search for new materials for active layers with a low detection limit and the ability to operate in a wide range of concentrations is an urgent task.…”