Ambient temperature selective ammonia gas sensor based on SnO2-APTES modifications

Abstract

Highlights  Molecular functionalized sensors were elaborated by two steps modification.  Characterization of modified sensors was carried out by ATR-FTIR.  Testing the sensors under gases was performed at room temperature.  Ester modified SnO2 sensor was sensitive and selective to ammonia gas.

A novel approach to a fully inkjet printed SnO2-based gas sensor on a flexible foil

“…Indeed, we notice that at temperatures below 225 °C, the conductance of SnO2 exposed to NH3 was lower than the one obtained under dry air. This phenomenon has been reported previously by Kamalpreet Khun et al [54] and by Hijazi et al [26]. They explained this phenomenon by different reaction mechanisms at low and high temperatures.…”

“… The first involves a surface functionalization of the SnO2 sensitive layer using an organic functional groups having different polarities, which leads to a change of the sensor response toward specific gases like ammonia [26].  The second implies the incorporation or the doping of atoms into the SnO2 structure [60].…”

“…The commonly sensitive elements used for gas sensors are the semiconductor metal oxides like SnO2, ZnO, WO3, CuO, NiO, TiO2, CeO2 etc. [24][25][26][27]. They are low cost, highly sensitive and have good thermal and structural stability.…”

HFIP‐Functionalized Co3O4 Micro‐Nano‐Octahedra/rGO as a Double‐Layer Sensing Material for Chemical Warfare Agents

“…As a result, a hole accumulation region will be generated on the surface owing to transfer of electrons from the conduction band to the chemisorbed oxygen species. This change gives the resistance of the sensor in air . After exposure of the sensors to DMMP molecules, the Co 3 O 4 crystals react with DMMP molecules through the methoxy group (O‐CH 3 ), which will bond with the adsorbed oxygen vacancies (O − ) on the surface of the Co 3 O 4 crystals and will lead to transfer of electrons from DMMP to the sensing materials because DMMP is a strong electron donor .…”

How the Chamber Design Can Affect Gas Sensor Responses

“…Metal oxides represent a very promising material for such kind of applications; they possess a broad range of electronic, chemical, and physical properties that allow them to be widely used and investigated in the detection of volatiles and other gases [2]. In this context, one of the most interesting metal oxide is tin oxide (SnO2), a n-type semiconductor with a direct wide band gap 3.62 eV at 300 K, and a variety of potential applications such as transparent conducting electrodes, solar cells and most importantly in gas sensing technology [3].…”