Ultra-fast response and highly selectivity hydrogen gas sensor based on Pd/SnO2 nanoparticles

It is still a challenging task to achieve the rapid detection of hydrogen (H2) with the rapid development of hydrogen energy sector. In this work, the H2 sensing capabilities of pristine and Pd-modified SnO2 nanoparticles with the size of ∼7 nm were systematically evaluated. The SnO2 nanoparticles were synthesized via hydrothermal method and Pd modification was performed using impregnation route. Pd modification remarkably upgraded the H2 sensing performances compared with the pristine SnO2 gas sensor. The working temperature of SnO2 decreased from 300 °C to 125 °C after Pd loading. Among the prepared Pd/SnO2 gas sensors, 0.50 at.% Pd/SnO2 sensor exhibited the highest response magnitude of 254 toward 500 ppm H2 and rapid response/recovery time of 1/22 s at 125 °C. The enhanced H2 sensing capabilities by Pd modification may be related to the catalytic effect and the resistance modulation.