Rapid and Selective NH3 Sensing by Porous CuBr


Date

2020-04-08

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric

Data

Abstract

Fast and selective detection of NH3 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 NH3 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) NH3 concentrations at 90% relative humidity is attained with outstanding selectivity (30–260) over typical confounders including ethanol, acetone, H2, CH4, 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.

Publication status

published

Editor

Book title

Volume

7 (7)

Pages / Article No.

1903390

Publisher

Wiley

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Breath analysis; Environmental monitoring; Gas sensors; Semiconductors; Wearables

Organisational unit

03510 - Pratsinis, Sotiris E. (emeritus) / Pratsinis, Sotiris E. (emeritus) check_circle
09794 - Güntner, Andreas / Güntner, Andreas check_circle

Notes

Funding

170729 - Integrated system for in operando characterization and development of portable breath analyzers (SNF)

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