Nonanal gas sensing properties of platinum, palladium, and gold-loaded tin oxide VOCs sensors

Analysis of Recovery Time of Pt-, Pd-, and Au-Loaded SnO2 Sensor Material with Nonanal as Large-Molecular-Weight Volatile Organic Compounds

“…After this exposure to nonanal, the resistance did not return to within 90% of its original value in 300 s, as shown in Table 1. In our previous study, nonanal was also tested on the non-aged Pt, Pd, Au/SnO 2 sensor, (21) where the sensor response value was also low (S = 17) at 250 °C, and sufficient resistance recovery was observed within 300 s. In this study, the sensor response value of the third nonanal analysis, after the seventh isoprene analysis, was slightly better than that of the first. However, the recovery rate [P(t)] of resistance was worse than the first time [P(300) = 24 vs 34%], as shown in Table 1.…”

“…(21) Before the preparation of thick films of sensing materials, a platinum comb-type electrode 7.5 mm 2 in area with a 10 µm gap and 10 µm line width was formed on a 4 × 4 mm 2 surface-oxidized Si substrate, and a Pt heater was patterned on the backside of the substrate. Pt (particle size: 2 nm), Pd (particle size: 4 nm), and Au (particle size: 3 nm) colloid suspensions (Tanaka Kikinzoku Kogyo K.K.)…”

“…However, the recovery of resistance was much slower after exposure to nonanal [t 10 > 300 s; P(300) = 32] than that of isoprene (t 10 = 212 s), as shown in Table 1. (21) 9.5 ppm nonanal 17 120 - …”

Effect of Noble Metal Addition on Co3O4-Based Gas Sensors for Selective NO Detection

“…(10) Therefore, the addition of a noble metal to these metal oxide semiconductors is critical for improving the sensitivity and selectivity of these gas sensors. (13,14) We reported that the NO gas sensing properties of the Pd-loaded Co 3 O 4 sensor with 0.1-30 wt% Pd content were estimated and the sensor with 10 wt% Pd content showed a high response and signal-to-noise ratio. (15) In this study, Co 3 O 4 powder with 10 wt% noble metal (Pd, Ag, Pt, and Au) content was prepared by the colloidal mixing method, and the responses of these sensors to 50 and 200 ppb NO in air were investigated, in reference to the response of a sensor based on pure Co 3 O 4 .…”

“…(15) In this study, Co 3 O 4 powder with 10 wt% noble metal (Pd, Ag, Pt, and Au) content was prepared by the colloidal mixing method, and the responses of these sensors to 50 and 200 ppb NO in air were investigated, in reference to the response of a sensor based on pure Co 3 O 4 . (14,15) To discuss the selectivity against other gases as an initial evaluation, their responses to H 2 in air were also investigated.…”