Electronic Asymmetric Distribution of RhCu Bimetallic Nanocrystals for Enhancing Trifunctional Electrocatalysis.

Developing the efficient and durable multifunctional electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is of significant importance for many electrochemical energy devices, such as water electrolyzers, metal-air batteries and fuel cells. Herein, the Rh-Cu alloy nanocrystals (NCs) are prepared with a simple wet-chemical approach. The tuning of morphology and the asymmetric electron distribution provide more efficient Rh-Cu bimetallic sites. Meanwhile, the incorporation of Cu into Rh lattice could reduce the oxidation of Rh-Cu bimetallic sites and increase the catalytic stability. Under the tuning of the composition, the drastically enhanced electrocatalytic activities of HER, OER and ORR are achieved in the Rh6Cu1 NCs with the small cell voltage of 1.55 V at 10 mA cm-2 for overall water splitting and maximum power density of 142.58 mW cm-3 for zinc-air battery with good stability, representing the best trifunctional electrocatalysts to the best of our knowledge. This work highlights the design and control of Rh-Cu NCs, which could be a potential alternative approach to trifunctional catalysis and further boost the development of the bimetallic electrocatalysts in the energy conversion system.