Benzylamine coupling is a very important reaction for the synthesis of imine but still faces many challenges.
Herein, we present a highly effective strategy towards the coupling reaction by using environmentally
friendly catalysts. These catalysts are composed of Cu/Cu2O/Cu3N heterostructures supported by C3N4
tubes and the composites were synthesized by one-step hydrothermal treatment followed by
calcination. Cu2O, Cu3N, and C3N4 all are responsive to visible light and the heterojunction formed can
greatly enhance the charge separation. When used as photocatalysts for oxidative self-coupling of
benzylamine at a low temperature of 323 K in air, Cu/Cu2O/Cu3N/C3N4 was able to give conversion and
selectivity values of up to 99% and 98%, respectively. The high efficiency of the catalysts is attributable to
their ability to generate large quantities of free radicals (such as $OH and $O2
) under visible-light irradiation