Biosynthesis of Ag-Pd bimetallic alloy nanoparticles through hydrolysis of cellulose triggered by silver sulfate.

We report a simple but efficient biological route based on the hydrolysis of cellulose to synthesize Ag-Pd alloy nanoparticles (NPs) under hydrothermal conditions. X-ray powder diffraction, ultraviolet-visible spectroscopy and scanning transmission electron microscopy-energy dispersive X-ray analyses were used to study and demonstrate the alloy nature. The microscopy results showed that well-defined Ag-Pd alloy NPs of about 59.7 nm in size can be biosynthesized at 200 °C for 10 h. Fourier transform infrared spectroscopy indicated that, triggered by silver sulfate, cellulose was hydrolyzed into saccharides or aldehydes, which served as both reductants and stabilizers, and accounted for the formation of the well-defined Ag-Pd NPs. Moreover, the as-synthesized Ag-Pd nanoalloy showed high activity in the catalytic reduction of 4-nitrophenol by NaBH.