Copper nanoparticles supported on MoO3 (Cu NPs/MoO3) were prepared by a green method using Sun spurge leaf extract. Cu NPs/MoO3 nanoparticles were characterized by X‐ray diffraction analysis, energy dispersive X‐ray analysis, scanning electron microscope and transmission electron microscope. The cata- lytic activity of this well‐defined material in three‐component CuAAC reac- tions was tested to produce 1,4‐disubstituted‐1,2,3‐triazoles in good to excellent yields in water as a green solvent. More importantly, the catalyst can be recovered and reused efficiently up to five consecutive cycles with no significant loss of catalytic activity.
