Nano-Schottky Junction-Engineered Pd/SnO2 Nanotube Array for Ultrasensitive Hydrogen Sensing at Room Temperature

Abstract

Low-concentration H2 detection is of significance due to its major concern for safety in practical applications. However, semiconductor chemiresistive gas sensors always suffer from high operating temperature and power consumption, as well as a limited range of concentration detection, which restricts their widespread use. Herein, we developed a 3D nanostructured gas sensor employing Pd nanoclusters decorated SnO2 nanotube array as the sensing layer. The sensor shows sensitive and selective properties for low-concentration H2 detection at room temperature, and the limit of detection was down to 1.6 ppb. It also shows good long-term stability as long as 100 days. Moreover, systematical characterizations are performed in conjunction with density functional theory (DFT) calculations to determine the impact of Pd/SnO2 junctions on the gas-sensing properties improvement. The engineering of the nano-Schottky junction allows us to expand the library for designing low-power consumption H2 sensors for wide applications.