An unconventional class of high-performance Pt alloy multimetallic nanowires (NWs) is produced by a general method. The obtained PtNi NWs exhibit amazingly specific and mass oxygen reduction reaction (ORR) activities with improvement factors of 51.1 and 34.6 over commercial Pt/C catalysts, respectively, and are also stable in ORR conditions, making them among the most efficient electrocatalysts for ORR.

Highly open metallic nanoframes represent an emerging class of new nanostructures for advanced catalytic applications due to their fancy outline and largely increased accessible surface area. However, to date, the creation of bimetallic nanoframes with tunable structure remains a challenge. Herein, we develop a simple yet efficient chemical method that allows the preparation of highly composition segregated Pt-Ni nanocrystals with controllable shape and high yield. The selective use of dodecyltrimethylammonium chloride (DTAC) and control of oleylamine (OM)/oleic acid (OA) ratio are critical to the controllable creation of highly composition segregated Pt-Ni nanocrystals. While DTAC mediates the compositional anisotropic growth, the OM/OA ratio controls the shapes of the obtained highly composition segregated Pt-Ni nanocrystals. To the best of our knowledge, this is the first report on composition segregated tetrahexahedral Pt-Ni NCs. Importantly, by simply treating the highly composition segregated Pt-Ni nanocrystals with acetic acid overnight, those solid Pt-Ni nanocrystals can be readily transformed into highly open Pt-Ni nanoframes with hardly changed shape and size. The resulting highly open Pt-Ni nanoframes are high-performance electrocatalysts for both oxygen reduction reaction and alcohol oxidations, which are far better than those of commercial Pt/C catalyst. Our results reported herein suggest that enhanced catalysts can be developed by engineering the structure/composition of the nanocrystals.

The layered molybdenum disulfide (MoS 2 ) nanostructured materials are of great interest for electrochemical energy storage and conversion and electrocatalytic water splitting. However, they still exhibit very limited performance because of their limited active sites. To create more efficient MoS 2 materials, herein, we develop a simple yet efficient approach to a unique column-like MoS 2 superstructure composed of edge-terminated MoS 2 nanosheets (CLET MoS 2 ). These MoS 2 nanosheets as building blocks with fully exposed active edges are oriented in a preferred manner, rendering CLET MoS 2 that exhibits excellent electrochemical performance in both lithium ion storage and hydrogen evolution reaction (HER). Compared with that of commercial MoS 2 , these hierarchical MoS 2 superstructures possess much higher specific capacity and superior cycling performance for lithium ion storage and excellent electrocatalytic activity and stability for HER with a very low Tafel slope of 39 mV decade −1 , showing their great potential applications in lithium ion batteries and water splitting.

No abstract

Herein, we report a facile strategy that allows one-pot preparation of highly open rhombic dodecahedral PtCu alloy nanoframes. Due to the highly open structures, the PtCu nanoframes exhibit enhanced catalytic performance in methanol electrooxidation, showing a new strategy to create highly active catalysts.