Nano Crystalline Porous Thin Film Hydrogen Storages

Abstract

The results of high-resolution transmission electron microscopy revealed that TiNx and VNx films consist of 150-200 nm particles, which boundaries contain nano-pores of 10-15 nm diameters. Particles themselves consist from randomly oriented 10-20 nm nano-grains. Examination of the absorption characteristics of VNx and TiNx films showed that the amount of absorbed hydrogen depends very little on the chemical composition of films, but it is determined by pore structure. The amount of absorbed hydrogen at 0.3 MPa and 20°C is 6-7 wt.%, whereas, the bulk of the hydrogen is accumulated in the grain boundaries and pores.