Hydrogen sensors based on Pt-decorated SnO2 nanorods with fast and sensitive room-temperature sensing performance

Hydrogen energy has been regarded as one of the most promising green and renewable energy in future society. The development and application of fast and cost-effective hydrogen sensors are of great significant for the safe application of hydrogen energy. In this work, high-performance semiconductor hydrogen sensors with fast room-temperature (RT) hydrogen response were fabricated by using Pt-decorated SnO2 nanorods. The SnO2 nanorods with tetragonal phase were synthesized through a hydrothermal method, and then decorated by Pt nanoparticles by a photochemical reduction method under UV irradiation. The hydrogen sensing performance of the SnO2 nanorods at RT were greatly enhanced after the Pt-decoration. The sensor response was gradually increased from 27.10% to 87.35% with Pt/Sn mol ratio increasing from 0 to 3.63%. Meanwhile, the response and recovery process were also accelerated with increasing Pt loading amount. The room-temperature response and recovery time of the sensor with Pt/Sn ratio of 3.63% was down to 0.33 and 29.60 s, respectively. The sensor also exhibited outstanding repeatability and selectivity against CO and CH4. Moreover, the impact of humidity on the sensor performance were also investigated. The sensor response was decreased with increasing environmental humidity, which could be partially recovered after the humidity was decreased. The remarkably accelerated sensor performance could be attributed to the catalytic property of Pt nanoparticles with spillover effect and the contribution of Pt-induced metal-semiconductor contact effect to the hydrogen response of the sensors.