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.