GS7.4 - Selective Formaldehyde Detection at low ppb Level with Microporous Membranes and SnO2 Sensors

Le résumé fourni par la source

A major challenge in gas sensing (e.g.air quality and breath analysis) is the selective detection of trace-level pollutants.While many gas sensors exhibit sufficient lower detection limit down to ppb, they lack selectivity.Here, we present a novel concept that combines (1) a membrane taking over the selectivity task by pre-separating the gas mixture with (2) a chemoresistive gas sensor detecting the analyte.The membrane is decoupled from the sensors to allow individual fabrication and independent operation.It consists of a zeolitic molecular sieve featuring adjustable separation properties to match the analyte.As proof-of-concept, a compact zeolite MFI/Al2O3 membrane is placed before a nonspecific Pd-doped SnO2 sensor.In fact, this system exhibits excellent selectivity (even in gas mixtures) to carcinogenic formaldehyde over ethanol, ammonia, acetone and isoprene (all > 100) at 50% relative humidity, superior to existing sensors.This novel concept can be extended to other tracers and it could facilitate a new class of selective and portable gas detectors.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.