In situ green synthesis of Cu-Ni bimetallic nanoparticles supported on reduced graphene oxide as an effective and recyclable catalyst for the synthesis of N-benzyl-N-aryl-5-amino-1H-tetrazoles

In the present work, for the first time we have designed a novel approach for the synthesis of N-benzyl-N-aryl-5-amino-1H-tetrazoles using reduced graphene oxide (rGO) decorated with Cu-Ni bimetallic nanoparticles (NPs). In situ synthesis of Cu/Ni/rGO nanocomposite was performed by a cost efficient, surfactant-free and environmentally benign method using Crataegus azarolus var. aronia L. leaf extract as a stabilizing and reducing agent. Phytochemicals present in the extract can be used to reduce Cu2+ and Ni2+ ions and GO to Cu NPs, Ni NPs and rGO, respectively. Analyses by means of FT-IR, UV-Vis, EDS, TEM, FESEM, XRD and elemental mapping confirmed the Cu/Ni/rGO formation and also FT-IR, NMR, and mass spectroscopy as well as elemental analysis were used to characterize the tetrazoles. The Cu/Ni/rGO nanocomposite showed the superior catalytic activity for the synthesis of N-benzyl-N-aryl-5-amino-1H-tetrazoles within a short reaction time and high yields. Furthermore, this protocol eliminates the need to handle HN3.