Enhanced ethanol sensing properties based on alpha -Fe sub(2)O sub(3)/In sub(2)O sub(3) hollow microspheres

alpha -Fe sub(2)O sub(3) and In sub(2)O sub(3) hollow microspheres were synthesized via a simple green hydrothermal route, and the alpha -Fe sub(2)O sub(3)/In sub(2)O sub(3) composite sample was prepared by mixing two products above together in a molar ratio of 1:1. Traditional ceramic tube structure gas sensors were fabricated and their gas sensing characteristics were obtained. The results indicated that the alpha -Fe sub(2)O sub(3)/In sub(2)O sub(3) sample showed an improved sensitivity and selectivity to ethanol, compared with either alpha -Fe sub(2)O sub(3) or In sub(2)O sub(3) sample. Moreover, the sensitivities of both In sub(2)O sub(3) and alpha -Fe sub(2)O sub(3)/In sub(2)O sub(3) sensors were good linear with gas concentrations (1-500 ppm) to ethanol, and the response was found to remain stable for 150 days. In addition, the gas sensing mechanism of ethanol detection has been discussed.