Bio-directed synthesis of platinum nanoparticles using aqueous honey solutions and their catalytic applications

The use of bio-derived products for the synthesis of nano sized materials is of enormous interest to modern nanobiotechnology. We have developed a novel green, bio-directed and economically feasible method for the synthesis of platinum nanoparticles and nanowires using a bio-derived product – honey. In the present method, the conversion of platinum ions into approximately 2.2 nm sized platinum nanoparticles was achieved with a reaction temperature of 100 °C in aqueous honey solutions. Longer thermal treatment produced platinum nanowires of length (5–15 nm), which were formed by the self-assembly of platinum nanoparticles. The prepared platinum nanostructures were characterized by UV–visible spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). SAED patterns, XRD patterns and the HR-TEM image confirm that the resulting platinum nanoparticles are highly crystalline and the structure is face-centered cubic (fcc). FT-IR analysis suggests that the obtained platinum nanoparticles were bound to protein through the carboxylate ion group. Catalytic application of these platinum nanostructures for the preparation of organic dye by the reaction of aniline with 4-aminoantipyrine in an acidic aqueous medium was also studied.