High-performance gas sensors can offer great potentials for monitoring and detection of volatile organic compounds (VOCs) in both domestic and industrial environment. In the present work, a new HCHO gas sensor was constructed with reduced graphene oxide (RGO) induced by the oximation reaction. The gas-sensing performance test results suggested that the RGO hydroxylamine hydrochloride (RGO/HA-HCl) sensor presented a high response of 75% at 16 ppm HCHO at room temperature, and a high selectivity for HCHO suffering little interference with high concentrations of volatile organic compounds, including methanol, ethanol, and methylbenzene, dichloromethane and water. Additionally, the RGO/HA-HCl sensor also showed a good long-term stability with RSD of 5.83% for a 15-day continuous sensing test, and the detection limit (DL) could reach 0.023 ppm under ambient conditions. Moreover, the mechanism for the high sensitivity and selectivity of formaldehyde was further established by in-situ gas chromatography mass spectrometry (GC–MS). This work would provide a reliable new HCHO gas sensor which could be used for monitoring and forewarning the emission of HCHO for a better protection and improvement of our environment.

高性能气体传感器可以为在家庭和工业环境中监测和检测挥发性有机化合物（VOC）提供巨大潜力。在目前的工作中，使用由肟化反应诱导的还原氧化石墨烯（RGO）构建了新的HCHO气体传感器。气体传感性能测试结果表明，RGO羟胺盐酸盐（RGO / HA-HCl）传感器在室温下在16 ppm HCHO上显示出75％的高响应，并且对HCHO的选择性高，几乎不受高浓度挥发物的干扰有机化合物，包括甲醇，乙醇和甲基苯，二氯甲烷和水。此外，RGO / HA-HCl传感器还显示出良好的长期稳定性，对于15天的连续感测测试，RSD为5.83％，并且检测极限（DL）可以达到0。在环境条件下为023 ppm。此外，通过原位气相色谱质谱法（GC-MS）进一步建立了甲醛的高灵敏度和选择性的机理。这项工作将提供一种可靠的新型HCHO气体传感器，该传感器可用于监测和预警HCHO的排放，从而更好地保护和改善我们的环境。