Synergistic effect of bimetallic Cu:Ni nanoparticles for the efficient catalytic conversion of 4-nitrophenol

The structural engineering of metallic nanoparticles opens a pathway for improving their catalytic activity. Herein, we report the hydrothermal synthesis of bimetallic nanoparticles differing in Cu–Ni molar ratio (Cu25Ni75, Cu50Ni50 and Cu75Ni25) and compare these with the properties of monometallic nickel and copper. Cu25Ni75 and Cu50Ni50 primarily exhibited a bimetallic composite structure, while Cu75Ni25 displayed a bimetallic alloy structure. The bimetallic system demonstrated better catalytic activity for the degradation of 4-nitrophenol in comparison to the monometals. In spite of a similar surface area and size, the Cu75Ni25 bimetallic alloy showed good recyclability with high catalytic activity towards 4-nitrophenol reduction that was 24 times higher than that of monometallic copper. Cyclic voltammetry studies revealed a higher oxidation current for Cu75Ni25, indicating that it possesses a better electron transfer rate, which facilitates catalytic activity. Our results highlight the importance of developing bimetallic interfaces for improving the efficiency of catalytic processes.