Mesoporous and/or macroporous SnO
2-based powders have been prepared and their gas-sensing properties as thick film sensors towards H
2 and NO
2 have been investigated. The mesopores and macropores of various SnO
2-based powders were controlled by self-assembly of sodium
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Mesoporous and/or macroporous SnO
2-based powders have been prepared and their gas-sensing properties as thick film sensors towards H
2 and NO
2 have been investigated. The mesopores and macropores of various SnO
2-based powders were controlled by self-assembly of sodium bis(2-ethylhexyl)sulfosuccinate and polymethyl-methacrylate (PMMA) microspheres (
ca. 800 nm in diameter), respectively. The introduction of mesopores and macropores into SnO
2-based sensors increased their sensor resistance in air significantly. The additions of SiO
2 and Sb
2O
5 into mesoporous and/or macroporous SnO
2 were found to improve the sensing properties of the sensors. The addition of SiO
2 into mesoporous and/or macroporous SnO
2 was found to increase the sensor resistance in air, whereas doping of Sb
2O
5 into mesoporous and/or macroporous SnO
2 was found to markedly reduce the sensor resistance in air, and to increase the response to 1,000 ppm H
2 as well as 1 ppm NO
2 in air. Among all the sensors tested, meso-macroporous SnO
2 added with 1 wt% SiO
2 and 5 wt% Sb
2O
5, which were prepared with the above two templates simultaneously, exhibited the largest H
2 and NO
2 responses.
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