Pd surface modification of SnO2-based nanorod arrays for H2 gas sensors

In this work, SnO₂ nanorod arrays have been deposited by inductively coupled plasma-enhanced chemical vapor deposition (PECVD) without any high temperature treatment or additional catalysis. The SnO₂ nanorods are connected at the root with a very thin seed layer on the substrate. The SnO₂ nanorods have a spatial distribution density of 350 mum^-2 and large surface area of around 108 m²/g. Pd was chemically modified on surface of the SnO₂ nanorods by spin coating. The sensitivity of the SnO₂ nanorod arrays increased around 4 times after doping with 1 layer of Pd, but decreased continuously with increasing Pd layers. The effect of the annealing temperature on the sensing properties was also studied and it was found that annealing at 500degC is enough to achieve better performance of the Pd-doped SnO₂ nanorod array sensor.