Wet Chemical Synthesis of Silver Nanowire Thin Films at Ambient Temperature

Novel silver nanowire thin films, which consist of interwoven bundles of single-crystalline silver nanowires about 30-40 nm in diameter, have been successfully synthesized on glass wall by mild chemical reduction in aqueous solutions of poly (methacrylic acid) at room temperature. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and UV-vis absorption spectroscopy have been used to characterize the obtained silver products. It was found that there existed a competition between precipitation of spherical particles, precipitation of individual nanowires, and formation of silver nanowire films. It was revealed that the negatively charged glass surface provided heterogeneous nucleation sites for the growth of bundles of silver nanowires. Appropriate pH values and polymer concentrations were crucial for the growth of dense silver nanowire films on the glass wall. A polymer-mediated heterogeneous nucleation and growth process has been proposed for the formation of the unique metal nanowire thin films.