Herein, SnO₂ QDs (<10 nm) with small size instead of conventional nanoparticles was employed to modify ZnFe₂O₄ to synthesize porous and heterogeneous SnO₂/ZnFe₂O₄ (ZFSQ) composites for gas sensing. By an immersion process combined with calcination treatment, the resultant porous ZFSQ composites with different contents of SnO₂ QDs were obtained, and their sensing properties were investigated. Compared with bare ZnFe₂O₄ and SnO₂ QDs, porous ZFSQ composites based-sensors showed much improved sensor response to acetone. For contrast, the sensor performance of ZFSQ composites was also compared with that of ZnFe₂O₄ sphere modified by SnO₂ nanoparticles with different size. The porous ZFSQ composite with 5 wt% SnO₂ QDs (ZFSQ-5) showed a better acetone sensing response than that of other ZFSQ composites, and it exhibited a high response value of 110–100 ppm of acetone and a low detection limit of 0.3 ppm at 240 °C. In addition to the rich heterojunctions and porous structure, the size effect of SnO₂ QDs was other indispensable reasons for the improved sensor performance. Finally, the ZFSQ-5 composite sensor was attempted to be applied for acetone sensing in exhaled breath, suggesting its great potential in monitoring acetone.

中文翻译：

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SnO2 量子点敏化 ZnFe2O4 球体，具有增强的丙酮传感性能

本文采用小尺寸的SnO ₂ QDs（<10 nm）代替传统的纳米颗粒来修饰ZnFe ₂ O ₄ ，合成用于气敏的多孔异质SnO ₂ /ZnFe ₂ O ₄（ZFSQ）复合材料。通过浸渍工艺结合煅烧处理，得到了不同SnO ₂量子点含量的多孔ZFSQ复合材料，并研究了其传感性能。与裸ZnFe ₂ O ₄和SnO ₂ QD相比，基于多孔ZFSQ复合材料的传感器对丙酮的传感器响应显着改善。为了对比，ZFSQ复合材料的传感器性能也与不同尺寸SnO ₂纳米粒子修饰的ZnFe ₂ O ₄球的传感器性能进行了比较。含有 5 wt% SnO ₂ QDs的多孔 ZFSQ 复合材料（ZFSQ-5）表现出比其他 ZFSQ 复合材料更好的丙酮传感响应，并且表现出 110-100 ppm 丙酮的高响应值和 0.3 的低检测限。 240°C 时为 ppm。除了丰富的异质结和多孔结构之外，SnO ₂ QDs的尺寸效应是提高传感器性能的另一个不可或缺的原因。最后，尝试将ZFSQ-5复合传感器应用于呼出气中的丙酮传感，表明其在丙酮监测方面的巨大潜力。