Tuning Coating Thickness of Iron Tetraphenyl Porphyrin on Single Walled Carbon Nanotubes by Annealing: Effect on Benzene Sensing Performance

摘要

The influence of post functionalization annealing in tuning the sensing properties of metalloporphyrin functionalized single walled carbon nanotubes (SWCNTs) based benzene sensors has been reported. Aligned SWCNTs framework is non-covalently functionalized by iron tetraphenyl porphyrin (FeTPP), followed by a systematic investigation of the annealing effect(s) on the functionalized structures. Structural (field emission scanning electron microscopy, atomic force microscopy), electrical (current–voltage, chemFET characteristics), spectroscopic (Raman), and sensing (chemiresistive) studies reveal that optimal annealing conditions lead to the efficient control of coating thickness and surface microstructure of the functionalizing entity, which allows the efficient participation of both sensing components during analyte detection. Optimized sensors bearing clear synergistic effects of FeTPP and SWCNTs could be obtained with features suitable for real-time monitoring of benzene that include detection window of 1 ppm–25 ppm at room temperature, sensitivity figure of 15.3% and response/recovery duration in the range of 14–31 s and 5–35 s, respectively.