Enhanced Metal-Support Interactions Boost the Electrocatalytic Water Splitting  of Supported Ruthenium Nanoparticles on a Ni3N/NiO Heterojunction at Industrial Current Density.

Developing highly efficient and stable hydrogen production catalysts for electrochemical water splitting (EWS) at industrial current densities remains a great challenge. Herein, we proposed a heterostructure-induced-strategy to optimize the metal-support interaction (MSI) and the EWS activity of Ru-Ni3N/NiO. Density function theory (DFT) calculations firstly predicted that the Ni3N/NiO-heterostructures can improve the structural stability, electronic distributions, and orbital coupling of Ru-Ni3N/NiO, compared to Ru-Ni3N and Ru-NiO, which accordingly decreases energy barriers and increases the electroactivity for EWS. As a proof-of-concept, the Ru-Ni3N/NiO catalyst with 2D Ni3N/NiO-heterostructures nanosheet array, uniformly dispersed Ru nanoparticles, and strong MSI, was successfully constructed in the experiment, which owns an excellent HER and OER activity with overpotentials of 190 mV and 385 mV at 1000 mA cm-2, respectively. Furthermore, the Ru-Ni3N/NiO-based EWS device can realize an industrial current density (1000 mA cm-2) at 1.74 V and 1.80 V under alkaline pure water and seawater conditions, respectively. Additionally, it also achieves a high durability of 1000 h (@ 500 mA cm-2) in alkaline pure water.