High sensitive hydrocarbon gas sensor utilizing cataluminescence of γ-Al2O3 activated with Dy3+

A new method using cataluminescence (CTL)-based gas-sensor detecting hydrocarbon in air is proposed. CTL is a kind of chemiluminescence (CL), which is emitted during catalytic oxidation of organic vapors, e.g., ethanol and acetone. By depositing Dy on the gamma-Al2O3 catalyst, we measured the extra CTL spectrum due to Dy3+ during the catalytic oxidation of hydrocarbon gas, while no such CTL was emitted from the gamma-Al2O3 catalyst without Dy. By investigating the luminescence mechanism of Dy, the existence of active species produced in a course of catalytic oxidation to excite Dy directly was clarified. The CTL-based gas-sensor using y-Al2O3 activated with Dy3+ has high sensitivity and linear characteristic. The detection limit of iso-butane in air is 0.2 ppm. (C) 2000 Elsevier Science S.A. All rights reserved.