Sayago Isabel, Sánchez-Vicente Carlos, Santos José Pedro
Institute for Physical and Information Technologies (ITEFI-CSIC), 28006 Madrid, Spain.
Nanomaterials (Basel). 2024 Dec 12;14(24):1994. doi: 10.3390/nano14241994.
Chemical nanosensors based on nanoparticles of tin dioxide and graphene-decorated tin dioxide were developed and characterized to detect low NO 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 concentrations (100 ppb) at room temperature. The sensors showed very good sensitivity and selectivity to NO with low cross-responses to the other pollutant gases tested (CO and CH). 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 or CH + NO, 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 (0.5 ppm), NO (0.5 ppm) + CO (5 ppm) and NO (0.5 ppm) + CH (10 ppm), respectively. In addition, the detection mechanisms were discussed and the possible redox equations that can change the sensor conductance were also considered.
基于二氧化锡纳米颗粒和石墨烯修饰的二氧化锡开发并表征了化学纳米传感器，用于检测低浓度的一氧化氮（NO）。通过滴铸法制备敏感层。利用扫描电子显微镜/能谱分析（SEM/EDX）来研究传感器的表面形态和元素组成。传感器的光激活使得在室温下能够检测超低浓度的NO（100 ppb）。该传感器对NO表现出非常好的灵敏度和选择性，对其他测试的污染气体（CO和CH）的交叉响应较低。研究了湿度和石墨烯的存在对传感器响应的影响。对比研究表明，引入石墨烯可提高传感器性能。在复杂气氛（潮湿空气中的CO + NO或CH + NO）中的检测证实了石墨烯传感器在接近实际条件下的高选择性。因此，对NO（0.5 ppm）、NO（0.5 ppm）+ CO（5 ppm）和NO（0.5 ppm）+ CH（10 ppm）的响应分别为600%、657%和540%。此外，还讨论了检测机制，并考虑了可能改变传感器电导的氧化还原方程式。
