Nanospherical Surface-Supported Seeded Growth of Au Nanowires: Investigation on a New Growth Mechanism and High-Performance Hydrogen Peroxide Sensors

In this paper, a novel strategy with a new growth mechanism for fast and large-scale growth of Au long nanowires on high-curvature SiO 2 nanospherical surfaces has been developed. The synthesis includes three steps, i.e., amino modification of SiO 2 nanospheres, Au seed loading on aminated SiO 2 nanospheres and subsequently, Au seed-mediated nanowire growth on SiO 2 nanospheres. The prepared Au nanowires (Au NWs) (exhibit long length, high aspect ratio, and good flexibility, and can naturally form the dense nanowire film, which is promising as a stable conductive electrode. In addition, the effect of synthetic conditions such as reactant feeding order, Au seeds and SiO 2 @Au seeds on the morphology of Au nanostructures (nanowires, nanoteeth, and nanoflowers) has been investigated. It is found that Au seeds and high-curvature SiO 2 nanospherical surfaces are necessary conditions for the successful preparation of Au NWs and nanowire films. The different growth mechanisms for Au NWs and nanoteeth have been proposed and discussed. Moreover, the novel nonenzymatic H 2 O 2 sensor based on Au NWs exhibits much enhanced performance such as higher sensitivity, stability, and selectivity, wider linear range and lower detection limit, compared with that of Au nanoparticles-based H 2 O 2 sensor.