Composition dependent structure and catalytic activity of nanostructured Cu-Ni bimetallic oxides

Nanostructured bimetallic oxides have garnered great attention in the field of catalysis. Here, we report the influence of structure and catalytic activity of composition tuned bimetal oxides CuO/NiO. Different ratio of Cu: Ni (0:100, 25:75, 50:50, 75:25 and 100:0) oxides were prepared via hydrothermal process and subsequently heat-treated at 600 °C for 4 hr. XRD and Raman spectroscopic analysis clearly indicated the co-existence of NiO and CuO phases in bimetallic oxides. The electron microscopic studies revealed a reduction in particle for bimetallic oxide than that of monometallic. The highest catalytic activity with good recyclability towards the reduction of 4-nitrophenol was observed for Cu50Ni50-600 having rate constant of 5.08 (s-1) x 10-3. The cyclic voltammetric investigation confirmed the high reactivity of Cu50Ni50-600 towards 4-nitrophenol by showing high oxidation current peak compared to other samples. The results show that the presence of CuO and NiO enhances the catalytic activity by their synergetic effect than mono metal oxides.