A straightforward and effective polyol route for the controllable synthesis of high-quality gold (Au) octahedra with uniform size is presented in an ethylene glycol solution. Large-scale Au octahedra with the size ranging from tens to hundreds of nanometers were selectively synthesized in high-yield. The surfaces of octahedral Au nanocrystals are smooth and correspond to {111} planes. Formation of Au nanooctahedra was attributed to the preferential adsorption of cationic surfactant poly(diallyldimethylammonium) chloride (PDDA) molecules on the {111} planes of Au nuclei that inhibited the growth rate along the <111> direction. The reduction rate of gold ions in the synthesis process can be rationally manipulated by acidic and basic solutions. This provides a facile and effective route to harvest Au octahedra with different dimensions. The synthetic strategy has the advantage of one-pot and requires no seeds, no foreign metal ions, and no pretreatment of the precursor, so that this is a practical method for controllable synthesis of Au octahedra. Size-dependent optical properties of Au octahedra were numerically and experimentally analyzed. The analysis shows that Au octahedra with sharp edges possess attractive optical properties, promising their applications to surface-enhancement spectroscopy, chemical or biological sensing, and the fabrication of nanodevices.

Pieces of eight: Single‐crystalline Au nano‐octahedra with well‐defined shape and tunable size can be synthesized by a modified polyol process. The octahedral Au nanocrystals have sharp corners and display optical properties that are sensitive to the crystal sizes and the truncation of the tips.

Immer acht: Einkristalline Au‐Nanooktaeder mit genau definierter Form und einstellbarer Größe konnten mit einem modifizierten Polyolprozess hergestellt werden. Die oktaedrischen Au‐Nanokristalle haben scharfe Ecken und optische Eigenschaften, die empfindlich auf die Kristallgröße und das Abschneiden von Spitzen reagieren.

We present a facile route to prepare bionic superhydrophobic coatings with striking supporting forces by fabricating hierarchical micro-/nanostructures on curved surfaces. The hierarchical structure was synthesized by decorating silver nanoparticles on a monolayer array of polystyrene (PS) microspheres. The monolayer array formed on a flat surface was transferred on a curved surface using silver acetate solution, which can then be converted into silver nanoparticles through thermal decomposition. The fabricated superhydrophobic coating on a convex tube exhibited a strong water-repellent property and supplied a high supporting force when it was floated on water surface.