Hydrogenation of C=N bonds on TiO2 surface: The effect of the Cu2O/TiO2 p-n heterojunction photocatalyst

As a widely used semiconductor photocatalyst, TiO2 has been explored in organic compounds hydrogenation. In this study, the hydrogenation of C=N bonds on the surface of TiO2 was accomplished for the first time utilizing Cu2O/TiO2 type-II (p-n) heterojunction. The probe reactions, hydrogenation of N-benzylphenylamine with benzyl alcohol, and N-methylation of amines with methanol exhibited that the hydrogenation of C=N bonds on TiO2 surface can be achieved through borrowing hydrogen reaction (BH, alcohols as hydrogen source). Additionally, the BH reaction rate could be improved by adding external H+ to the reaction system. The catalytic activity of Cu2O/TiO2 was discovered to remain at an efficient level even after six reaction cycles.