Porous ZnFe₂O₄ double-shell, york-shell, and solid microspheres are synthesized using a combination of hydrothermal method and thermal treatment (carried out at appropriate temperature determined via gravimetry). The specific surface area is varied by adopting different heating rates during the thermal treatment; double-walled structure is formed at higher heating rates. Gas sensors based on ZnFe₂O₄ double-shell microspheres showed a promising response (when compared to york-shell and solid microspheres), when tested with ∼20 ppm acetone (R_air/R_gas = 13.6). There is little or no response to interferential gases, including ethanol, methanol, xylene, toluene, benzene, carbon monoxide, hydrogen sulfide and nitrogen dioxide. The gas sensor showed an almost linear response to acetone concentration and a low detection limit for acetone of 0.13 ppm (making it compliant with analytic requirements for acetone-threat or diabetes-breathalyzer tests). The observed gas sensing performance (includes response time ∼6–10 s at 206 °C operating temperature and good cyclability) suggests that the ZnFe₂O₄ double-shell microspheres presented here are prospective sensing materials for acetone detection.

ZnFe ₂ O ₄多孔双壳，卵黄壳和固体微球是通过水热处理和热处理（在适当的温度下通过重量分析法进行测定）的结合而合成的。通过在热处理过程中采用不同的加热速率来改变比表面积。双壁结构是在较高的加热速率下形成的。当使用约20 ppm的丙酮（R_空气/ R_气体）测试时，基于ZnFe ₂ O ₄双壳微球的气体传感器显示出有希望的响应（与卵壳和固体微球相比） = 13.6）。对干扰气体的响应很少或没有响应，包括乙醇，甲醇，二甲苯，甲苯，苯，一氧化碳，硫化氢和二氧化氮。气体传感器对丙酮浓度显示出几乎线性的响应，并且对丙酮的检出限较低，为0.13 ppm（使其符合对丙酮威胁或糖尿病-血液透析仪测试的分析要求）。观察到的气体传感性能（包括在206°C的工作温度下约6-10 s的响应时间和良好的循环性）表明，此处介绍的ZnFe ₂ O ₄双壳微球是用于丙酮检测的潜在传感材料。