Hydrogen Adsorption Studies Using Surface Acoustic Waves on Nanoparticles

Nanoparticles made from metals such as Vanadium and Niobium, on the order of 10 nm, are deposited on a quartz surface acoustic wave resonator (SAWR) using a Nd:YAG pulsed laser deposition system. Utilizing the high Q and resonant frequency of the SAWR, mass changes due to adsorption on the order of 0.1 nanogram can be measured. Thus, this technique enables the controlled collection of isolated nanoparticles with total mass at the 10s of nanogram level and subsequent sorption of hydrogen in them. At room temperature and 4.9 bar of hydrogen pressure, we find 1.75 wt% H absorption ratio in V nanoparticles of 10 nm nominal size.