Rational Design of PdPt Nanoalloys Sensitized Mesoporous SnO2 for High-Performance Methane Sensing Applications

Methane (CH 4 ) serves as a commonly utilized fuel gas in various industrial and everyday settings. Given its flammable, explosive, and greenhouse gas nature, the real-time monitoring of its concentration in the air holds vital importance across practical applications. The tetrahedral structure of methane molecules features high bond energies, posing a significant challenge for chemical detection over metal oxide-sensitive layers. In this research, a multicomponent assembly method is used to synthesize ordered mesoporous tin oxide (SnO 2 ) with uniform large mesopores (≈ 10 nm) and pore wall functionalized with Pd x Pt nanoalloys (≈ 2.5 nm), and due to the unusual C–H bond activation capabilities of Pd x Pt nanoalloys and semiconducting properties of mesoporous SnO 2 , the obtained Pd 2 Pt@m-SnO 2 is used to fabricate gas sensors which showcases a wide applicability range in detecting concentrations ranging from 50 to 20 000 ppm at 400 °C, and it yields a substantial CH 4 response of 9.19 (1000 ppm) and an ultralow limit of the detection value of 175.9 ppb. Furthermore, the sensor is successfully incorporated into a portable device, evidencing its capability for accurate CH 4 detection in real-world scenarios.