Iodide-Switched Deposition for the Synthesis of Segmented Pd–Au–Pd Nanorods: Crystal Facet Matters

Segmented metallic nanorods with well-defined shapes and controllable components play an important role on the systematic investigation of their shape-dependent catalytic, electric, and plasmonic properties of metal nanostructures. Unfortunately, the shape and composition of segmented nanorods are difficult to be precisely controlled via colloidal methods. Here, we reported the growth of Pd–Au–Pd bimetallic heterostructures by using Au 5-fold twinned bipyramids (BPs) as seeds, with KI as a structure-directing reagent. Through a series of control experiments we revealed that two parameters were identified as critical factors for the growth of segmented Pd–Au–Pd nanorods. First, 5-fold twinned Au BPs with low-index end facets and high-index side facets function as a unique template for directed growth. Second, iodide can switch the deposition of Pd on the Au BPs. A high concentration of iodide is believed to block the high-index facets of the Au BPs and lower the reaction kinetics to promote the selective growth of two Pd segments on the Au BPs. As a result, uniformed segmented Pd–Au–Pd nanorods were obtained. The segmented nanorods exhibit intense extinction in the near-IR range and could be a potential candidate for plasmon-based biological applications such as thermal therapy

Controlled Synthesis of Palladium Concave Nanocubes with Sub-10-Nanometer Edges and Corners for Tunable Plasmonic Property

Developing new strategies for tuning the plasmonic properties of palladium nanostructures is of both fundamental and technological interest due to their potential applications in plasmonic hydrogen sensing, in situ surface-enhanced Raman spectroscopy for catalysis, and solar energy harvesting. In this work, a new strategy of tuning the localized surface plasmon resonance (LSPR) property of Pd nanocrystals by selectively sharpening their edges and corners is reported. Through a Cu­(II)-assisted seed-mediated growth approach, sub-10-nm sharp edges and corners were grown on regular Pd nanocubes. The LSPR peaks of the as-formed concave Pd nanocubes could be tuned across the visible spectrum by simply controlling their sizes. Cu­(II) was found to selectively activate the fast growth of Pd atoms along the [110] and [111] directions of the cubic Pd seeds and promote the formation of this new type of Pd concave nanocubes. This strategy of building Pd sharp edges and corners may be applicable for the design of new plasmonic nanostructures by using seeds of different metals, sizes, shapes, and crystal structures

Validation of finite element model by comparing to existing literature.

<p>Comparison of finite element prediction and cadaveric experiment results from Funk et al., 2002 on ground reaction force (GRF) and tibial reaction force (TRF) under pure impact and impact with Achilles tendon loaded. (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154435#pone.0154435.s001" target="_blank">S1 Table</a>)</p

Von Mises and Tresca stresses of the calcaneus and talus trabecular at different impact velocities.

<p>Von Mises and Tresca stresses of the calcaneus and talus trabecular at different impact velocities.</p

Finite element model of the foot and ankle complex.

<p>Finite element model of the foot and ankle complex showing the top and side view of the parts geometry and demonstrating the boundary and load conditions used in the simulation.</p

Maximum von Mises and Tresca stress with yielding volume of trabecular calcaneus against impact velocity.

<p>(<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154435#pone.0154435.s003" target="_blank">S3 Table</a>).</p

Drilling process and the general process: action in the dotted box occurred at some time or not, which is decided by tutors.

<p>Drilling process and the general process: action in the dotted box occurred at some time or not, which is decided by tutors.</p

Maximum von Mises and Tresca stress with yielding volume of trabecular talus against impact velocity.

<p>(<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154435#pone.0154435.s004" target="_blank">S4 Table</a>).</p