Lanthanum oxide @ antimony-doped tin oxide with high gas sensitivity and selectivity towards ethanol vapor

• The La2O3@Sb-SnO2 was found to be highly sensitive and selective towards ethanol vapor.
• Typically, under optimized operating temperature of 250, the sensitivities of La2O3@Sb-SnO2 towards 1000 ppm of ethanol vapor and CO were 59.8 and 2.77, the ratio was 21.6.
• The high sensitivity of La2O3@Sb-SnO2 towards ethanol vapor is suggested to be attributed by the barrier depression of p–n junction, while its anti-interference towards CO is maybe mainly due to the strongly basic of La2O3.

An ethanol-sensing powder (La2O3@Sb-SnO2), mixture composed of 1.00 wt.% La2O3 and 99.00 wt.% Sb-doped SnO2 (Sb-SnO2), was found to possess enhanced sensitivity towards ethanol: typically, for La2O3@Sb-SnO2, the ratio of the response towards 1000 ppm ethanol vapor to that of 1000 ppm CO is 26.1 (60.0/2.3) under operating temperature of 250 °C; while for Sb-SnO2, the ratio is only 4.5 (9.0/2.0). A suggestive mechanism on enhanced ethanol sensing is discussed.