Simple solid-state chemical synthesis and gas-sensing properties of spinel ferrite materials with different morphologies

Spinel ferrite materials with different morphologies were synthesized by simple solid-state chemical reactions under mild reaction conditions and their gas-sensing properties were investigated in detail. It was found that all sensors based on the as-prepared materials had high responses, low working temperatures, rapid response/recovery characteristics, good selectivity and long-term stability to methanal and ethanol. Among them, ZnFe2O4 exhibited the best response, which was attributed to its intrinsic semiconductor nature and suitable microstructure. The response value reached 37.3 for 100 ppm of methanal at 260 °C and 29.1 for 100 ppm of ethanol at 300 °C. The response and recovery times were not longer than 5 s and 26 s. This study has yielded helpful insights to explore gas-sensing materials with good comprehensive performance.