A scalable hydrothermal approach is presented for the synthesis of large quantities of palladium nanowires (PdNWs) from palladium(II) chloride precursor, mediated by the introduction of low concentrations of Cu(II) ions via copper(II) acetate. Optimal yield occurs at a Pd/Cu molar ratio of ~12,500, whereby the product nanowires are observed to have the highest aspect ratios yet reported for Pd nanocrystals, with diameters of 20 nm and lengths greater than 9 μm. X-ray diffraction, electron microscopy, and X-ray photoelectron spectroscopy measurements confirm that the as-synthesized nanowires are indeed metallic crystalline Pd with a 5-fold twinned cross-section. Control experiments with no trace metal additives yielded no wire-like particles, suggesting that Cu ions play a critical role in the synthesis that has not previously been reported. It is hypothesized that Cu ions act as oxygen scavengers to prevent the oxidative etching of the twinned Pd seeds that eventually grow into elongated nanowires as opposed to uniform nanoparticles.  The  large aspect  ratio  of the nanowires  enables them to be dynamically manipulated in an optoelectronic tweezers (OET) device, which we  demonstrate as a way to enhance their applicability for catalysis and hydrogen sensing.<br/>

Copper-mediated synthesis and optoelectronic trapping of ultra-high aspect ratio palladium nanowires

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.