Enhanced H<sub>2</sub> Sensing of SnO<sub>2</sub> Nanowires Functionalized with Pt and Pd Catalyst Nanoparticles

Abstract

SnO2 nanowires with a tetragonal structure were synthesized by thermal evaporation of tin grains at 900 °C. The obtained SnO2 nanowires were doped with Pt and Pd. The morphology, crystal structure, and H2 sensing properties of undoped, Pt-doped, and Pd-doped SnO2 nanowires were investigated. SnO2 nanowires were approximately 30–200 nm in diameter and several tens of micrometers in length. Gas sensors based on undoped, Pt-doped, and Pd-doped SnO2 nanowires showed a reversible response to H2 at an operating temperature of RT–300 °C. The response was improved in the order undoped < Pt-doped < Pd-doped SnO2 nanowire sensors under the same conditions. The highest response upon exposure to 1000 ppm H2 was 252.9 at 100 °C for Pd-doped SnO2 nanowire sensor. The results demonstrated that impurity doping improved the sensor response and lowered the operating temperature at which the sensor response was maximized.