Ni@Ru and NiCo@Ru Core–Shell Hexagonal Nanosandwiches with a Compositionally Tunable Core and a Regioselectively Grown Shell

Abstract

The development of highly active electrocatalysts is crucial for the advancement of renewable energy conversion devices. The design of core-shell nanoparticle catalysts represents a promising approach to boost catalytic activity as well as save the use of expensive precious metals. Here, a simple, one-step synthetic route is reported to prepare hexagonal nanosandwich-shaped Ni@Ru core-shell nanoparticles (Ni@Ru HNS), in which Ru shell layers are overgrown in a regioselective manner on the top and bottom, and around the center section of a hexagonal Ni nanoplate core. Notably, the synthesis can be extended to NiCo@Ru core-shell nanoparticles with tunable core compositions (Ni Co @Ru HNS). Core-shell HNS structures show superior electrocatalytic activity for the oxygen evolution reaction (OER) to a commercial RuO black catalyst, with their OER activity being dependent on their core compositions. The observed trend in OER activity is correlated to the population of Ru oxide (Ru ) species, which can be modulated by the core compositions.

Iridium‐Chromium Oxide Nanowires as Highly Performed OER Catalysts in Acidic Media

“…The existing strategies can be classified into three major categories: (1) the introduction of specific components to generate composites, including those containing conductive and acid‐resistant materials as supports, alloys with nonprecious metals (Ni, Co, Cu, etc. ), core‐shell structures and various mixed metal oxide composites; (2) controlling special morphologies to create and expose additional active sites, such as two‐dimensional catalysts featuring ultrathin sheets, needles, or nanowires or three‐dimensional structures featuring abundant mesopores; (3) the formation of particular structures including amorphous IrO x , SrIrO 3 perovskite, SrTi 0.67 Ir 0.33 O 3 perovskite, Y 2 Ir 2 O 7 pyrochlore and Y 2 Ru 2 O 7‐δ pyrochlore . Despite these advances, the overpotential at 10 mA cm −2 is generally ∼300 mV and the catalysts are typically stable for less than 10 h. Their catalytic activity and stability can be even worse when Ir contents are reduced.…”

Recent Progress of Ruthenium‐based Nanomaterials for Electrochemical Hydrogen Evolution

“…[25a,30] For bi/multi-metallic nanostructures, interface engineering was the key to optimize the electrocatalysts since atomic arrangements at the interface directly determined the HER performance. [31] For instance, Xiaoqing Huang's group fabricated RuÀ Ni sandwiched nanoplates (SNs) with Ru grown at the end of Ni pillar (Figure 2a), [32] in which abundant interface was formed between Ni and Ru phase. Then it gradually turned into NiO x /Ru interface because of the air oxidation.…”

Defect‐Rich Copper‐doped Ruthenium Hollow Nanoparticles for Efficient Hydrogen Evolution Electrocatalysis in Alkaline Electrolyte

“…[17,18] In addition, alloying Ru with appropriate metals can modulate its electronic structure in order to regulate catalytic activity. [19][20][21] Herein, we report hollow Copper (Cu)-doped Ru nanocrystals derived from Cu@Ru core@shell nanoparticles (NPs) as efficient electrocatalysts for HER in alkaline media. The hollow structures could offer a large surface area in addition to exposing more active sites.…”