Indium Oxide—Single-Walled Carbon Nanotube Composite for Ethanol Sensing at Room Temperature

Abstract

Utilizing a sol-gel synthesis, indium oxide is grown on the surface of oxidized single-walled carbon nanotubes (SWCNT) to form a hybrid material with high conductivity and sensitivity toward certain organic vapors. The room-temperature sensing of dilute ethanol and acetone vapors on the surface of indium oxide/SWCNT hybrid material is studied using electrical conductance experiments in a nonoxidizing environment. Through testing of variously calcinated materials, it was observed that the degree of annealing greatly affects the material's response to acetone and ethanol, such that the intermediate calcination condition yields the best sensitivity. DFT simulations are used to study the interface between defective SWCNT and indium oxide, as well as the interaction between ethanol and acetone molecules with the indium oxide/SWCNT hybrid material.