Preparation of Fe2O3(0.9)–SnO2(0.1) by hydrazine method: application as an alcohol sensor

Nanocrystalline Fe2O3(0.9)–SnO2(0.1) powders have been prepared using a hydrazine method by adding hydrazine monohydrate to an aqueous solution of ferric nitrate nanohydrate, (Fe(NO3)3·9H2O) and tin tetra chloride (SnCl4), followed by washing and drying. This material has been characterized by different techniques such as gravimetric-differential thermal analysis (TGA/DTA), X-ray diffraction (XRD). Sensors made from this material have been proved to be highly sensitive and selective in the detection of ethanol. The sensitivity for ethanol has been compared with a 10 wt.% of ZrO2 and SnO2 loaded in Fe2O3. The ethanol sensitivity of pure and Pt doped Fe2O3(0.9)–SnO2(0.1) and Fe2O3(0.9)–ZrO2(0.1) has been investigated for its electrical resistance. The high sensitivity of the sensor to the ethanol could be explained on the basis of a SnO2, ZrO2 activity that invokes the acid–base properties of sensing materials towards the sensitive detection of ethanol vapor in air. Its cross-sensitivity to other gases like CH4, CO, and H2 has also been carried out.