Precise preparation of WO3@SnO2 core shell nanosheets for efficient NH3 gas sensing.
J Colloid Interface Sci
; 568: 81-88, 2020 May 15.
Article
in En
| MEDLINE
| ID: mdl-32088454
ABSTRACT
Development of high-performance ammonia (NH3) sensor is imperative for monitoring NH3 in the living environment. In this work, to obtain a high performance NH3 gas sensor, structurally well-defined WO3@SnO2 core shell nanosheets with a controllable thickness of SnO2 shell layer have been employed as sensing materials. The prepared core shell nanosheets were used to obtain a miniaturized gas sensor based on micro-electro-mechanical system (MEMS). By tuning the thickness of SnO2 layer via atomic layer deposition, a series of WO3@SnO2 core-shell nanosheets with tunable sensing properties were realized. Particularly, the sensor base on the fabricated WO3@SnO2 nanosheets with 20-nm SnO2 shell layer demonstrated superior gas sensing performance with the highest response (1.55) and selectivity toward 15 ppm NH3 at 200 °C. This remarkable enhancement of NH3 sensing ability could be ascribed to the formation of unique WO3-SnO2 core-shell heterojunction structure. The detailed mechanism was elucidated by the heterojunction-depletion model with the help of specific band alignment.
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1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Colloid Interface Sci
Year:
2020
Document type:
Article
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