Enhancing performance of FSP SnO2-based gas sensors through Sb-doping and Pd-functionalization

✍ Scribed by Katharina Großmann; Krisztina E. Kovács; David K. Pham; Lutz Mädler; Nicolae Barsan; Udo Weimar

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 701 KB
• Volume: 158
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2011.06.044

✦ Synopsis

Via flame spray pyrolysis (FSP), SnO 2 gas sensing layers have been doped with 0.01-4 wt% Sb as well as 0.01 wt% Pd in combination with 1 wt% Sb. Characterization of these materials through X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analysis, and transmission electron microscopy (TEM) revealed particle grain sizes and crystallinity unchanged by the presence of Sb and/or Pd. The addition of Sb to SnO 2 resulted in the significant decrease in baseline resistance; up to two orders of magnitude in dry air at 300 • C and three orders of magnitude in humid air at 300 • C, which is significant for FSPprepared gas sensors with high porosity and low particle coordination number since they typically suffer from high baseline resistance. While the baseline resistance was improved with Sb-doping, the sensor signal (R 0 /R gas ) remained constant over all concentrations explored. Moreover, regarding the surface functionalization of SnO 2 with Pd in combination with Sb-doping, the reduction of baseline resistance was preserved without influencing sensor signal.