Ultrasensitive and anti-interference near-room-temperature H2 MEMS detectors based on Pt-functionalized WO3 hierarchical architectures

The development of highly sensitive hydrogen sensors with low operating temperatures is crucial for the safe utilization of hydrogen. Practical operating environments demand not only high sensitivity but also immunity to both humidity fluctuations and interference from other reducing gases, especially CO. In this work, hierarchical architectures comprising WO 3 nanosheets (NS) assembled on WO 3 microspheres (M) is deliberately designed and successfully synthesized via a two-step solvothermal method. Subsequently, Pt is functionally loaded onto the surfaces, adopting various morphologies and serving multiple functions for H 2 sensing. Notably, the optimal operating temperature is reduced to 50 °C while achieving exceptional sensing characteristics: an ultrahigh response of 8372.2 toward 1200 H 2 , a swift 2 s response time, outstanding selectivity with immunity to CO interference, excellent humidity immunity, and robust long-term stability. The mechanism underlying the superior sensing capability is systematically investigated to elucidate the performance enhancement. This work presents a pioneering approach to constructing high-performance, anti-interference gas sensors through hierarchical architecture engineering, offering new insights into the design and application of advanced sensing materials.