Premium
H 2 S Dosimetry by CuO: Towards Stable Sensors by Unravelling the Underlying Solid‐State Chemistry
Author(s) -
Werner Sebastian,
Glaser Clarissa,
Kasper Thomas,
Lê Trung Nghia Nguyên,
Gross Silvia,
Smarsly Bernd M.
Publication year - 2022
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202103437
Subject(s) - nanorod , raman spectroscopy , chemistry , dosimeter , drop (telecommunication) , conductance , nanotechnology , dosimetry , analytical chemistry (journal) , chemical engineering , materials science , environmental chemistry , computer science , medicine , telecommunications , physics , mathematics , engineering , combinatorics , optics , radiology
The precise detection of the toxic gas H 2 S requires reliable sensitivity and specificity of sensors even at minute concentrations of as low as 10 ppm, the value corresponding to typical exposure limits. CuO can be used for H 2 S dosimetry, based on the formation of conductive CuS and the concomitant significant increase in conductance. In theory, at elevated temperature the reaction is reversed and CuO is formed, ideally enabling repeated and long‐term use of one sensor. Yet, the performance of CuO tends to drop upon cycling. Utilizing defined CuO nanorods we thoroughly elucidated the associated detrimental chemical changes directly on the sensors, by Raman and electron microscopy analysis of each step during sensing (CuO→CuS) and regeneration (CuS→CuO) cycles. We find the decrease in the sensing performance is mainly caused by the irreversible formation of CuSO 4 during regeneration. The findings allowed us to develop strategies to reduce CuSO 4 formation and thus to substantially maintain the sensing stability even for repeated cycles. We achieved CuO‐based dosimeters possessing a response time of a few minutes only, even for 10 ppm H 2 S, and prolonged life‐time.