Highly Sensitive and Selective SnO<sub>2</sub>-Gr Sensor Photoactivated for Detection of Low NO<sub>2</sub> Concentrations at Room Temperature
Chemical nanosensors based on nanoparticles of tin dioxide and graphene-decorated tin dioxide were developed and characterized to detect low NO<sub>2</sub> concentrations. Sensitive layers were prepared by the drop casting method. SEM/EDX analyses have been used to investigate the surfac...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-12-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/14/24/1994 |
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| Summary: | Chemical nanosensors based on nanoparticles of tin dioxide and graphene-decorated tin dioxide were developed and characterized to detect low NO<sub>2</sub> concentrations. Sensitive layers were prepared by the drop casting method. SEM/EDX analyses have been used to investigate the surface morphology and the elemental composition of the sensors. Photoactivation of the sensors allowed for detecting ultra-low NO<sub>2</sub> concentrations (100 ppb) at room temperature. The sensors showed very good sensitivity and selectivity to NO<sub>2</sub> with low cross-responses to the other pollutant gases tested (CO and CH<sub>4</sub>). The effect of humidity and the presence of graphene on sensor response were studied. Comparative studies revealed that graphene incorporation improved sensor performance. Detections in complex atmosphere (CO + NO<sub>2</sub> or CH<sub>4</sub> + NO<sub>2</sub>, in humid air) confirmed the high selectivity of the graphene sensor in near-real conditions. Thus, the responses were of 600%, 657% and 540% to NO<sub>2</sub> (0.5 ppm), NO<sub>2</sub> (0.5 ppm) + CO (5 ppm) and NO<sub>2</sub> (0.5 ppm) + CH<sub>4</sub> (10 ppm), respectively. In addition, the detection mechanisms were discussed and the possible redox equations that can change the sensor conductance were also considered. |
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| ISSN: | 2079-4991 |