Fe2O3– Modified Cr2O3 thick Films: Ethanol Sensor

Thick films of pure Cr2O3 were prepared by screen-printing technique. The surfaces of these films were modified by dipping them into 0.01 M aqueous solution of ferric chloride (FeCl3) for different intervals of time, followed by firing at 5500C for 30 min. firing results the oxidation of FeCl3 additive in to Fe2O3. The characterizations and the gas sensing properties of pure and surface activated Cr2O3 thick films have been investigated. The sensor gives response to Ethanol gas at 350OC. The quick response and fast recovery are the main features of this sensor. The effects of microstructure and activators concentration on the gas response, selectivity, response time and recovery reducing gases were studied and discussed.