Developing high-response, low-cost H2 sensors is critical for real-time H2 monitoring in the new energy era. In this work, ultra-low content (0.07 wt%) single-atom Pt-loaded SnO2/MEMS H2 sensors were prepared by an extended two-step annealing method, enabling ppb-level H2 sensing with low power consumption. At the optimal operating temperature of 201 °C, the sensor showed a response of 55.0 to 100 ppm H2, which is 9.17 times that of the pure SnO2 sensor. Compared with SnO2 sensors loaded with Pt via traditional impregnation, its optimal operating temperature is reduced by nearly 30 °C, and its response value is increased by 45.0. Additionally, the sensor exhibited a fast response time of 2.3 s and a limit of detection as low as 36 ppb. Mechanistic studies reveal that,, compared to traditional nanoparticle-modified material, the single-atom Pt-modified material exhibits a higher adsorbed oxygen content and enhanced surface oxidation activity. These results indicate single-atom Pt enhances the active oxygen level, underscoring its critical role in boosting H2-sensing performance.
Li et al. (Mon,) studied this question.