Effect of water vapor on Pd-loaded SnO2 nanoparticles gas sensor

Nan Ma; Koichi Suematsu; Masayoshi Yuasa; Tetsuya Kida; Kengo Shimanoe

doi:10.1021/am509082w

Effect of water vapor on Pd-loaded SnO2 nanoparticles gas sensor

ACS Appl Mater Interfaces. 2015 Mar 18;7(10):5863-9. doi: 10.1021/am509082w. Epub 2015 Mar 9.

Authors

Nan Ma, Koichi Suematsu, Masayoshi Yuasa, Tetsuya Kida¹, Kengo Shimanoe

Affiliation

¹ §Department of Applied Chemistry and Biochemistry, Kumamoto University, Kumamoto 860-8555, Japan.

PMID: 25734500
DOI: 10.1021/am509082w

Abstract

The effect of water vapor on Pd-loaded SnO2 sensor was investigated through the oxygen adsorption behavior and sensing properties toward hydrogen and CO under different humidity conditions. On the basis of the theoretical model reported previously, it was found that the mainly adsorbed oxygen species on the SnO2 surface in humid atmosphere was changed by loading Pd, more specifically, for neat SnO2 was O(-), while for 0.7% Pd-SnO2 was O(2-). The water vapor poisoning effect on electric resistance and sensor response was reduced by loading Pd. Moreover the sensor response in wet atmosphere was greatly enhanced by loading Pd. It seems that the electron depletion layer by p-n junction of PdO-SnO2 may impede OH(-) adsorption.

Keywords: CO; H2; Pd loading; SnO2 nanoparticles; oxygen adsorption; water vapor.