NG.6 - SnO 2 nanosheets functionalized with PdPt bimetal and their selective detection of carbon monoxide and methane
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- New Materials for Gas Sensing
- G. Li, Y. Fan - NEST Lab, Department of physics, College of Science, Shanghai University, Shanghai (China), Z. Cheng, Q. Xiang, X. Wang, J. Xu - NEST Lab, Department of chemistry, College of Science, Shanghai University, Shanghai (China)
- 354 - 355
PdPt bimetal nanoparticles (~2.7 nm) were synthesized via Pd(acac)2 and Pt(acac)2 reduction in oleylamine with borane tributylamine complex. Then the SnO2 nanosheets with PdPt nanoparticles (NPs) on their surface (0.5, 1, 1.5 wt%) were finally obtained by self-assembly. The composition and morphology of obtained PdPt/SnO2 composites were characterized by XRD, TEM and XPS. Their gas sensing properties were carefully studied to detect hazardous gases (CH4 and CO) in the coalmines. The results demonstrated that 1P-PdPt/SnO2-A composite could not only effectively detect CO at 90 ℃, but also detect CH4 at 320℃. Furthermore, compared with 1P-PdPt/SnO2-B obtained by traditional reduction method, 1P-PdPt/SnO2-A sensor displayed superior CO response (25 to 50 ppm) and CH4 response (5.3 to 1000 ppm) at their optimum working temperature. The dramaticly improved sensing performance can be attributed to the enhanced catalytic dissociation of the molecular adsorbate on the PdPt NPs surfaces and the repaid diffusion of the resultant active species to the oxide surface. On the other hand, PdPt NPs with uniform particle size and high dispersion on the oxide surface created more Schottky barrier-type junctions resulting in greater resistance changes during the reaction. Our present results demonstrate bimetal NPs have great potential in improving the gas sensitive performance of metal oxide semiconductors (MOSs).