Palladium nanocubes decorated on a one-dimensional ZnO nanorods array for use as a hydrogen gas sensor

This study demonstrates the development of a novel structure by synthesizing Pd nanocubes (NCs) decorated on vertical ZnO nanorods (NRs) applied to a resistive-type gas sensor. The shape control of Pd NCs with close {111} packing effects remarkably enhances the catalytic activity and capacity for H-2 adsorption compared to that of {100}. The as-prepared structure with high surface-to-volume ratio exhibited robust sensing performance with a strong response of 74% at 100 degrees C. The speed of the chemisorptions process through diffusion pathway in Pd NCs showed short response and recovery times of about 1.98 and 2.04 min, respectively, towards 10,000 ppm (1%) H-2 at 100 degrees C. Pd NCs expansion at H-2 atmosphere were suggested being a dominant factor of the spillover effect that allowed a detection limit as low as 1 ppm at room temperature. In addition, the sensor operating temperature ranged from room temperature to 200 degrees C. (C) 2015 Elsevier B.V. All rights reserved.