Enhanced Ethanol Detection: A High-Performance MEMS Sensor Utilizing Pt-Modified SnO2-TiO2 Composite Nanomaterials

Ethanol sensors with low energy consumption and high performance have been applied in a wide range of areas. In this work, Pt-modified SnO 2 -TiO 2 composite nanomaterials prepared through ball milling and impregnation-reduction are fabricated for constructing microelectromechanical systems (MEMS) ethanol sensor. Tiny Pt nanoparticles are found uniformly dispersed on SnO₂-TiO₂. High quality gas-sensitive films are concentrated in the functional area of the MEMS chip. The loading of Pt significantly enhances the response to ethanol and reduced the optimal operating temperature. The 1.5% platinum-modified composite (A-ST) demonstrates a significant improvement in sensitivity to 50 ppm ethanol, with its response rising from 21.3 to 52.1, while the optimal operating temperature is reduced by 28°C, dropping from 288°C to 260°C. The limit of detection (LOD) is 240 ppb. This enhancement is primarily due to the n-n junction at the interface between SnO 2 and TiO 2 , along with the chemical and electronic sensitization effects generated by Pt on SnO 2 -TiO 2 .