One-step synthesis of nickel–iron layered double hydroxides with tungstate acid anions via flash nano-precipitation for the oxygen evolution reaction

Abstract

Layered double hydroxide materials with two-dimensional structures and rich diversity have proved to be very promising candidates for non-precious metal electrocatalysis of the oxygen evolution reaction. We utilized a flash nano-precipitation (FNP) synthetic strategy to produce nickel–iron layered double hydroxides with tungstate anions, which simultaneously optimizes the intrinsic and extrinsic activity of the electrocatalyst. The high-valent metal W⁶⁺ was introduced into NiFe-LDH in the form of WO₄²⁻, which not only increases the diversity of metal species but also optimizes the electronic structure. Furthermore, the flash nano-precipitation synthesis method used changes the morphological structure of the material and thus provides more edge active sites for the oxygen evolution reaction. This led to the fact that NiFe-WO₄-LDH prepared from FNP has excellent electrocatalytic activity compared to the pristine materials we prepared. By combining the classical theory of chemical precipitation processes, it can be found that the flash nano-precipitation synthetic strategy can achieve a certain degree of separation of nucleation and growth processes by adjusting experimental parameters. The simple, efficient and scalable flash nano-precipitation synthesis method will provide new routes for metal-based electrocatalyst materials.