Open AccessRapid and Selective NH 3 Sensing by Porous CuBr
Author(s) -
Güntner Andreas T.,
Wied Markus,
Pineau Nicolay J.,
Pratsinis Sotiris E.
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201903390
Subject(s) - materials science , relative humidity , porosity , methanol , acetone , nanotechnology , acetic acid , selectivity , chemical engineering , chemistry , organic chemistry , composite material , catalysis , meteorology , physics , engineering
Fast and selective detection of NH 3 at parts‐per‐billion (ppb) concentrations with inexpensive and low‐power sensors represents a long‐standing challenge. Here, a room temperature, solid‐state sensor is presented consisting of nanostructured porous (78%) CuBr films. These are prepared by flame‐aerosol deposition of CuO onto sensor substrates followed by dry reduction and bromination. Each step is monitored in situ through the film resistance affording excellent process control. Such porous CuBr films feature an order of magnitude higher NH 3 sensitivity and five times faster response times than conventional denser CuBr films. That way, rapid (within 2.2 min) sensing of even the lowest (e.g., 5 ppb) NH 3 concentrations at 90% relative humidity is attained with outstanding selectivity (30–260) over typical confounders including ethanol, acetone, H 2 , CH 4 , isoprene, acetic acid, formaldehyde, methanol, and CO, superior to state‐of‐the‐art sensors. This sensor is ideal for hand‐held and battery‐driven devices or integration into wearable electronics as it does not require heating. From a broader perspective, the process opens exciting new avenues to also explore other bromides and classes of semiconductors (e.g., sulfides, nitrides, carbides) currently not accessible by flame‐aerosol technology.