Hydrogen storage phenomenon in amorphous phase of hydrogenated carbon nitride

A hydrogen storage characteristic of the amorphous phase of hydrogenated carbon nitride (a-CNx:H) deposited using a gas mixture of CH4 and N-2 by a chemical-vapor-deposition method enhanced by electron-cyclotron-resonance plasma was evaluated under high-pressure hydrogen atmosphere. The hydrogen content in the sample at 300 K and 77 K was directly measured using a volumetric analysis established for evaluation of hydrogen absorption of metal alloys. The contents of stored hydrogen in the sample under 12 MPa were determined to be 1.1 wt.% and 2.2 wt.% at 300 K and 77 K, respectively. The contents of stored hydrogen in the sample were larger than those of a-CNx:H deposited from the dissociated reaction of CH3CN and BrCN. The results of the storage behavior of hydrogen and infrared absorption suggest that the mechanism of hydrogen storage might be explained as chemical and physical absorption.