Layered double hydroxides as a robust catalyst for water oxidation through strong substrate-catalytic layer interaction

Abstract

Electrochemical preparation of hydrogen permits a way to meet our energy and environmental issues, but the anodic reaction is kinetically slow and thus is the bottleneck in the overall water splitting. Achieving cost-effective electrocatalysts represents a big challenge for practical water oxidation. Herein, We report the tuning of the local electron structure of nickel-iron layered double hydroxides (NiFe LDH) by achieving a highly coupled interface between active sites and the current collector. Our developed NiFe-LDH/Fe catalysts as the anode can provide 10 mA cm−2 at 1.455 V vs. RHE with a Tafel slope of only 32.7 mV dec−1. Simultaneously, the catalyst has high catalytic stability. Combined with the X-ray photoelectron spectroscopy and density functional theory calculation, the coupling interface between the substrate and catalytic layer can effectively regulate the electron density of the Fe sites, which is the main reason for the high catalytic ability of the layered double hydroxide catalyst.