During the detection of industrial hazardous gases, like formaldehyde (HCHO), the selectivity is still a challenging issue. Herein, an alternative HCHO chemosensor that based on the tin oxide nanoparticles is proposed, which was obtained through a facile hydrothermal method. Gas sensing performances showed that the optimal working temperature located at only 180 °C, the response value of 79 via 50 ppm HCHO was much higher than that of 35 at 230 °C. However, the compromised test temperature was selected as 230 °C, taking into account the faster response/recovery speeds than 180 °C, named 20/23versus 53/60 s, respectively. The response (35) of the SnO2 nanoparticles-based sensor to 50 ppm of HCHO is about 400% higher than that of bulk SnO2 sensor (9), especially when the gas concentration is 1 ppm, SnO2 nanoparticles also has a higher sensitivity which may possibly result from more exposed active sites and small size effect for nanoparticles than for bulk ones. The gas sensor based on SnO2 nanoparticles can be utilized as a promising candidate for practical low-temperature detectors of HCHO due to its higher gas response, excellent response–recovery properties, and perfect selectivity.

中文翻译：

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合成具有高灵敏度和良好选择性的用于甲醛检测的 SnO2 纳米粒子

在检测甲醛 (HCHO) 等工业有害气体时，选择性仍然是一个具有挑战性的问题。在此，提出了一种基于氧化锡纳米颗粒的替代 HCHO 化学传感器，该传感器是通过简便的水热法获得的。气敏性能表明，最佳工作温度仅位于 180 °C，79 via 50 ppm HCHO 的响应值远高于 35 在 230 °C 下的响应值。然而，考虑到比 180°C 更快的响应/恢复速度，折衷的测试温度选择为 230°C，分别命名为 20/23 和 53/60 秒。基于 SnO2 纳米颗粒的传感器对 50 ppm HCHO 的响应 (35) 比散装 SnO2 传感器 (9) 高约 400%，尤其是当气体浓度为 1 ppm 时，SnO2 纳米颗粒也具有更高的灵敏度，这可能是由于纳米颗粒比散装颗粒暴露更多的活性位点和小尺寸效应所致。基于 SnO2 纳米颗粒的气体传感器由于其较高的气体响应、优异的响应恢复特性和完美的选择性，可用作实际的 HCHO 低温检测器的有希望的候选者。