Large Mesoporous Tin Dioxide Powders for Gas Sensor Materials-Effects of Various Additives on the Mesostructure and the H_2 Sensing Properties

Preparation of large mesoporous tin dioxide (lm-SnO_2) under various conditions was attempted by utilizing a self-assembly of a triblock copolymer,P123:(EO)_(20)(PO)_(70)(EO)_(20) or F127:(EO)_(106)(PO)_(70)(EO)_(106)(EO:ethylene oxide and PO: propylene oxide).The sensor fabricated from calcined lm-SnO_2 powder,which had been prepared by using P123 as a template,Na_2SnO_3 as a tin source,and TEOS as an additive ([TEOS]/[Na_2SnO_3]=0.5 in the precursor solution),showed the largest response to 1×10^(-3) hydrogen at 350℃among the sensors tested.The existence of two kinds of SnO_2 particles with different sizes (ca.100 nm and several nm in diameter) may be important to improve the hydrogen sensing properties drastically.

Preparation of large mesoporous tin dioxide （1m-SnO2） under various conditions was attempted by utilizing a self-assembly of a triblock copolymer, P 123：（EO）20（PO）70（EO）20 or F 127：（EO）106（PO）70（EO）106 （EO： ethylene oxide and PO： propylene oxide）. The sensor fabricated from calcined lm-SnO2 powder, which had been prepared by using P123 as a template, Na2SnO3 as a tin source, and TEOS as an additive （[TEOS]/[Na2SnO3] = 0.5 in the precursor solution）, showed the largest response to 1× 10^-3 hydrogen at 350℃ among the sensors tested. The existence of two kinds of SnO2 particles with different sizes （ca. 100 nm and several nm in diameter） may be important to improve the hydrogen sensing properties drastically.