Phytic acid-modified NiFe-PBA stacked by π–π force for reinforcement electrocatalytic water oxidation†

Prussian blue analogues (PBAs) with a unique three-dimensional (3D) open metal framework structure and easily adjustable composition have been widely used in the oxygen evolution reaction (OER) under alkaline conditions. Herein, disintegrative PA-tPBA/NF (d-PA-tPBA/NF) was prepared by an ion-exchange reaction, phytic acid (PA) etching and mild thermal activation using Ni(OH)₂ layered nanosheets loaded on nickel foam (NF) as a precursor. Due to the optimization of the NiFe-PBA@Ni(OH)₂ heterostructure and π–π stacking force on the electron transfer structure, a stable high-speed charge transfer channel has been successfully constructed. Therefore, the OER overpotential required to transport 10 mA cm⁻² is only 250 mV, especially with a significant Tafel slope of 47.9 mV dec⁻¹. Furthermore, the d-PA-tPBA/NF||d-PA-tPBA/NF system achieved a current density of 10 mA cm⁻² with a cell voltage of only 1.55 V. This study provides a promising strategy for exploring efficient OER electrocatalysts derived from PBAs.