Catalytic reduction of 4-nitrophenol over graphene supported Cu@Ni bimetallic nanowires

Abstract

Abstract Catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) over high-performance non-noble metal catalysts is attracting intensive attention. Herein, we report a graphene supported Cu@Ni bimetallic nanowires catalyst by a facile liquid phase reduction method with the assistance of an external magnetic field. The morphology and structure of the composite are studied by SEM, TEM and XPS. The vibrating sample magnetometer (VSM) is used to analyze its magnetic properties. Owing to the synergistic effect of graphene and bimetallic nanowires, the catalyst shows superior catalytic performance and excellent stability. The results of catalysis exhibit an extraordinary rate constant (1.16 min−1) and activity factor (5.81 min−1 mg−1) at room temperature, which are much higher than a majority of non-noble metal catalysts, even noble metal catalysts. Also, compared with noble metal catalyst, the novel catalyst possesses ferromagnetism, which facilitates the separation of catalyst and reaction system, and guarantees recyclability. Moreover, a possible synergistic catalytic mechanism based on the fact that electron transfer between copper-nickel nanowires and graphene has been proposed. It is believed that the novel catalyst has a great importance for the application of nanowires in the field of catalysis.