Nanostructures of Pd-Ni alloy deposited on carbon fibers for sensing hydrogen

摘要

Pd-Ni alloy nanofilm and nanoparticles with various sizes have been electrodeposited on carbon fibers through controlling potential pulses. The two types of Pd-Ni alloy nanostructures can be used to detect hydrogen gas at room temperature. The dependence of H_2 sensing behavior on sizes of the nanofilm and nanoparticle has been discussed. The results show that response time decreases with hydrogen concentration increasing. In the two ranges of 0-2.8% and 3.6-6% H_2 gas surroundings, response of nanofilm increases with hydrogen concentration, but slightly decreases after exposure to 2.8-3.6% H_2 due to rearrangement of the particles in the nanofilm sensor. For nanoparticles sensor, response increases with hydrogen concentration between 0% and 6%. Both of them display good stability and reversibility. H_2 sensing by the Pd-Ni alloy nanostructures depends on the synthesis of volume expansion of the particles or film, the change of energy barrier at the interface and formation of Pd-H in H_2 gas. The recovery time is shorter in air due to the presence of oxygen than in pure argon.