Production of Reduced Al Nanoparticles from Al Oxide by Applying High Voltage Pulses to Solutions

TLDR: In this paper, the authors investigated the possibility of reducing metal oxide in a metal by using high-voltage pulses in order to save electrical consumption power compared with conventional methods that use high-temperature and high-pressure plasma such as arc discharge.

Abstract: Metal nanoparticles have become attractive as original materials for nano-inks and nano-pastes, which are used in printed electronics. Synthesizing various metal nanoparticles has been researched. We investigated the possibility of reducing metal oxide in a metal by using high-voltage pulses in this paper. This method should save electrical consumption power compared with conventional methods that use high-temperature and high-pressure plasma such as arc discharge. Reduced Al nanoparticles were obtained by applying high-voltage pulses to solutions. By analyzing elements and the composition of reduced Al nanoparticles by STEM and EDX, a large amount of reduced Al nanoparticles with diameters of a few 100 nm and thin oxide film of around 1 nm on metal surfaces were produced in experiments for reducing Al oxide. It was found from hydrogen generation using reduced Al nanoparticles by applying high-voltage pulses to solutions to evaluate reduction rate that a high reduction efficiency of 97% was obtained at maximum. We concluded that using high-voltage pulses for reduction can be suitably applied to printed electronics because the oxide film on reduced Al nanoparticles is thin. Also, because this method is similar to laser ablation in liquids using pulse lasers, the similarities were discussed in this paper.