Pd and Cu-Pd nanoparticles supported on multiwall carbon nanotubes for H2 detection

Abstract

Simple, cost-effective, and reproducible devices have been prepared for the detection of H2 at room temperature. Pd, Cu and bimetallic Cu-Pd nanoparticles (prepared by the reduction-by-solvent method) have been loaded on a MWCNT deposit avoiding the use of surfactants or complicated techniques. The devices based on pure Pd nanoparticles have shown a high H2 sensitivity in the studied H2 concentration range with low response and recovery times. However, the addition of Cu in the metallic nanoparticles does not result in a considerable improvement. Furthermore, the Pd and Cu-Pd/MWCNTs-based sensors have kept part of their H2 sensitivity when they have been tested in an O2-depleted atmospheres, which is an altogether new finding compared to Pd-based systems. Through these experiments it has been possible to conclude how the main H2 detection mechanism is the electron transfer from the nanoparticles (when the PdHx is formed) to the carbon nanotubes.