Metal oxide based gas sensing is promising to realize the effective detection of formaldehyde from the breathing gas, which is of great significance to lung cancer monitoring in the budding period. Seeking for novel materials with controlled microstructure and surface characteristics, while improving the sensing limit is still a highly desirable challenge. In this work, the hierarchical porous LaFeO₃ is explored for this purpose by using a low-cost, simple and mature method. By tuning the quantity of F108 structuring agent and calcined temperature, the corresponding gas-sensing properties can be adjusted and optimized. The results indicate that the LaFeO₃ with 0.5 g F108 possess the best gas-sensing property with sensing response of 116 toward 50 ppm formaldehyde at 125 °C. Importantly, the trace detection capacity is as low as 50 ppb, which is among the lowest value in the record of formaldehyde detection. Further detailed analysis indicates that the special hierarchical porous structure with high surface area and pore volume should be responsible for the improved sensing performance. These results suggest that construct hierarchical porous structure is a promising method to attain superior gas-sensing properties and LaFeO₃ can be potentially used for accurate, inexpensive, real-time, and painless detection of lung cancer.

基于金属氧化物的气体传感技术有望实现有效呼吸气体中甲醛的检测，这对于萌芽期肺癌的监测具有重要意义。在提高感测极限的同时，寻求具有可控的微观结构和表面特性的新型材料仍然是非常理想的挑战。在这项工作中，为此目的，通过使用低成本，简单而成熟的方法来探索分层多孔LaFeO ₃。通过调整F108结构化剂的数量和煅烧温度，可以调整和优化相应的气敏特性。结果表明，LaFeO ₃含0.5 g F108的化合物具有最佳的气体传感性能，在125°C下对50 ppm甲醛的传感响应为116。重要的是，痕量检测能力低至50 ppb，这是甲醛检测记录中的最低值。进一步的详细分析表明，具有高表面积和孔体积的特殊分层多孔结构应负责改善感测性能。这些结果表明，构造分级的多孔结构是获得优异的气敏特性的有前途的方法，LaFeO ₃可以潜在地用于准确，廉价，实时且无痛地检测肺癌。