Interfacial electronic engineering of Ru/FeRu nanoparticles as efficient trifunctional electrocatalyst for overall water splitting and Zn-air battery

•Ru and FeRu with a carbon shell on N-doped carbon (Ru-FeRu@C/NC) is constructed.•The Ru-FeRu@C/NC exhibites excellent HER, OER and ORR activity in alkaline medium.•A water splitting cell powered by a Zn–air battery is built using Ru-FeRu@C/NC.•Interfacial charge distribution accounts for the improved activity of Ru-FeRu@C/NC. Rational design of multi-functional electrocatalyst for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is critical to energy conversion and storage technologies such as water splitting and metal-air batteries. However, explorations of specific interface structures for catalysts are still limited and challenging. Herein, a novel core–shell architecture comprising of Ru and FeRu hybrid enwrapped with a carbon shell anchored on nitrogen-doped carbon substrate (Ru-FeRu@C/NC) was constructed. Specifically, the interfacial electronic interaction between Ru and FeRu regulate the electron configuration and broaden the electron transfer pathway to boost its electrocatalytic performance. Particularly, Ru-FeRu@C/NC required ultralow overpotentials of 23 and 345 mV to drive a current density of 10 mA cm−2 for HER and OER, respectively, and a positive half-wave potential of 0.90 V versus reversible hydrogen electrode (RHE) for ORR. Furthermore, an electrocatalytic water splitting cell powered by a Zn–air battery was successfully fabricated using Ru-FeRu@C/NC as the “one-in-all” electrocatalyst. The present work paves the way for design and construction of efficient multifunctional electrocatalyst in energy conversion and storage.