Preparation and Gas-Sensing Properties of CdFe_2O_4 Semiconductor Materials

摘要

The gas-sensing materials, CdFe_2O_4, were prepared by inverse titration chemical coprecipitation with FeSO_4·7H_2O and CdCl_2·2.5H_2O. After calcinations at 300°C ～ 700°C for 1h, respectively, n-type semiconductor gas-sensing materials with inverse spinel structure were obtained. Effects of the calcining temperature on the phase constituents and microstructure were characterized. The crystallite size of powders sintered at 700°C for 1h is 82 nm and dispersity good. Sensors based on CdFe_2O_4 were fabricated, and the gas-sensing properties were determined for using reducing gases. The results demonstrated that the sensors based on CdFe_2O_4 had good sensitivity and good selectivity to C_2H_5OH at 400°C. The difference in response for various tested gases might be attributed to absorption of reducing gases and reaction between these gases and the absorbed oxygen.