Palladium nanoparticle and decorated carbon nanotube for electrochemical hydrogen storage

Abstract

This study proposes a multicomponent system for hydrogen storage. An electrochemical evaluation was used as a simple and accurate technique to assess the storage capacity. A porous silicon substrate was fabricated using an electrochemical anodization process and decorated with palladium nanoparticles using the electroless method. The hybrid substrate underwent chemical vapor deposition for 45 min. Since the deposited palladium nanoparticles could act as potential catalysts, carbon nanotubes grew properly over hybrid structure. The final sample was obtained through post-treatment by palladium nanoparticles using the same electroless method. This triplet sample was characterized using field emission scanning electron microscopy and X-ray diffraction. Galvanostatic charge/discharge experiments were used to conduct electrochemical evaluations of proposed electrode. A maximum hydrogen storage capacity of 537 mAh/g (∼2.05 wt.%) was achieved for the triple-structure sample. The measurements demonstrate that the storage capacity of the triple-structure sample was reduced by a factor of 0.05% after 100 cycles. Although the obtained storage capacity is far from DOE targets, optimized structures based on the proposed electrode may be further developed as an efficient storage system.