La₂（WO₄）₃/SnO₂ヘテロ接合に基づく超高速応答室温トリエチルアミンセンサー

Triethylamine (TEA), a volatile chemical marker released during seafood spoilage, not only indicates food freshness but also poses respiratory hazards, underscoring the need for reliable gas sensing. Current TEA detection technologies are often constrained by high operating temperatures, limited sensitivity in the ppb range, and sluggish response/recovery behavior, leading to excessive energy use and restricted real-world applicability. To overcome these limitations, this study focuses on developing a room-temperature TEA sensor capable of ultrasensitive and rapid detection, supporting both energy-efficient operation and sustainable monitoring solutions.

We successfully synthesized SnO₂ hollow spheres and La₂(WO₄)₃ nanoparticles via a solvothermal method and constructed La₂(WO₄)₃/SnO₂ (LSO) nanocomposites with the aim of developing a highly efficient sensor for triethylamine (TEA) detection. The results show that the LSO exhibited a notable enhancement in TEA gas sensing properties at room temperature. Specifically, it was observed that the LSO-4 heterojunctions exhibited response to 100 ppm TEA could reach to 5.24, which was approximately 3.14 times better than that of pure SnO₂. Density functional theory (DFT) calculations confirmed the enhanced TEA adsorption capacity of the LSO heterojunction, while clarifying the underlying electron transfer mechanism. Practical application tests showed that the sensor could effectively detect TEA, demonstrating excellent sensitivity, stability, and repeatability, thereby providing feasibility for its application in monitoring of harmful gases in the environment.

This work reports the first example of fabrication La₂(WO₄)₃/SnO₂ heterojunctions for gas sensors. The sensors can detect ppb level TEA gas at room temperature, and meanwhile, the sensors have the advantage of ultrafast response and recovery, which is not normal for the room temperature gas sensor, which thus support their practical application in the field of food quality monitoring and harmful gas control.