A 2D FeCo LDH/TiN/NC van der Waals Heterojunction: Electron Redistribution Enhances Trifunctional Electrocatalysis.

Two-dimensional van der Waals heterojunctions (2D vdWHs) have garnered significant interest owing to their ability of efficiently interfacial electron transfer, tunable band structures, and high structural stability. Nevertheless, the utilization of 2D vdWHs as multifunctional electrocatalysts is still rarely explored. In this work, we synthesized a 30% FeCo LDH/TiN/NC electrocatalyst via high-temperature solid-state and hydrothermal methods, featuring a 2D vdWH architecture in which FeCo LDH nanosheets are uniformly anchored onto the TiN/NC substrate. The resulting electrocatalyst exhibits remarkable trifunctional activity and stability for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), comparable to those of commercial catalysts. The superior electrocatalytic performance is attributed to the interfacial electron redistribution, in which the electron transfer from TiN/NC to FeCo LDH enhances charge transfer kinetics and increases the number of active sites during electrochemical reactions. Moreover, the 30% FeCo LDH/TiN/NC electrocatalyst shows great promise for applications in both zinc-air batteries (ZABs) and overall water splitting. This study underscores the potential of 2D vdWHs and offers valuable insights for the design of advanced multifunctional electrocatalysts.