Cu₂O/UiO-66-NH₂ composite photocatalysts for efficient hydrogen production from ammonia borane hydrolysis

Ammonia borane (NH₃BH₃, AB) is a chemical hydride with a high hydrogen capacity of 19.6 wt%, which makes it a promising hydrogen carrier. Cuprous oxide (Cu₂O) is one of the most active photocatalysts for AB dehydrogenation at ambient conditions. However, the instability due to photocorrosion and high charge recombination are the main drawbacks of practical application. In this work, Cu₂O is coupled with a metal-organic framework (MOF) as a composite photocatalyst (Cu₂O/UiO-66-NH₂), which demonstrates a better photocatalytic performance in AB hydrolysis than its pure counterpart samples because of the heterojunction configuration. The Z-scheme charge transfer pathway in Cu₂O/UiO-66-NH₂ composite can improve charge separation, hydrogen production efficiency, photocatalyst stability, and reduce activation energy. The optimum composite photocatalyst comprising 50 wt% Cu₂O loading shows the highest hydrogen evolution yield of almost 2.3 equivalent H₂ from AB hydrolysis.