Metal Alloying Effect on the Catalytic Activity of Ag-Pt Nanoparticles for 4-Nitrophenol Reduction

In the astonishing field of nanotechnology, the metallic nanoparticles (NPs) are well entrenched as the subject of immense research because of their promising use in catalysis.^1-3 Herein, we present Ag-Pt bimetallic alloy NPs synthesized in aqueous suspension without using any stabilizer and owing to their synergistic and alloying effect between the metals, these alloy NPs have shown enhanced catalytic performance in the reduction of 4-nitrophenol to 4-aminophenol. An alloy of Ag and Pt have not been observed in bulk due to the vast immiscibility of these metals. In nanosized regime, these prepared Ag-Pt alloy NPs not only show higher catalytic efficiency than its mono-metals but also eliminates the induction time as seen in pure Ag NPs. The reaction monitored by UV-Visible (UV-Vis) spectroscopy at a wavelength of 400 nm displays the isosbestic points in the UV-Vis spectra in accordance with the most published results. High-resolution transmission electron microscope (HR-TEM) analysis shows that the silver-rich Ag-Pt alloy NPs have a spherical shape and size of 4 nm. By varying the metal ratio of Ag-Pt alloy NPs, have presented them as low-cost catalysts due to the fact that the highest catalytic activity was achieved at a relatively low content of Pt.

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