Hydrogen production by cracking of ammonium hydroxide using liquid-phase plasma on the modified TiO2 photocatalysts

Ammonia is a promising material as a direct source of green hydrogen production. This paper reports a method for mass production of hydrogen from liquid NH3(NH4OH) through a photocatalytic decomposition reaction using liquid plasma. In this reaction, the highest hydrogen production rate was observed in the TiO2 photocatalyst doped with N and metal ions as a photocatalyst sensitive to visible light with a low bandgap. At this time, the hydrogen production rate was obtained as about 142 L/g∙h. This is due to the high photoactivity of the visible light-sensitive photocatalyst in liquid plasma emitting strong visible light and ultraviolet light. The H2 production rate obtained from the decomposition of liquid NH3 by plasma discharge to the catalyst was higher than the H2 production rate obtained from the NH3 electrolysis process.