Fabrication of Pd/ Ni Alloy Nanotubes Via Electrospinning for High Performance Hydrogen Detection

Abstract

Hydrogen is one of the most important “next generation energy sources”, which is free for environment pollution, with water as the only emission. Due to the danger of hydrogen explosion when mixed with air, as well as the low specific heat capacity of hydrogen, the temperature required for combustion can be reached immediately even a little heat absorbed. Therefore, it’s necessary to search an effective way to monitor hydrogen leakage at room temperature.In this study, the Pd based hydrogen sensor was investigated. During the transduction process, volumetric expansion occurred due to the hydrogen absorption at room temperature to achieve safe hydrogen detection. Previous research indicated that Pd/Ni alloy films/ nanofibers can achieve higher catalytic activity, stability and sensitivity than pure Pd films/nanofibers due to the synergistic effect between Pd and Ni 1 ,2,3 . But both the films and nanofibers structures have limited specific surface area and therefore limited exposed hydrogen adsorption sites. To overcome these problems, we fabricated the porous Pd nanotubes alloyed with Ni by using Polyvinylpyrrolidone (PVP) and SiO2 templates electrospinning route, then the PVP and SiO2 templates were selectively removed by calcination and etching 4 , respectively. The sensing performance was measured by monitoring the resistance curves of sensing platform at various hydrogen concentrations. Compared to Pd/Ni nanofibers structures, tubular structures achieved lower LOD and higher sensitivity which are attributed to the high surface area and abundant hydrogen adsorption active sites. High performance Pd/Ni nanotubes can be successfully fabricated in an effective and facile approach for hydrogen detection at room temperature. At last, the effects of the concentration of Ni in Pd on the sensing performance was also investigated.