Prussian Blue Analogues Derived Hollow FeCoP Nanocubes for Electrocatalytic Overall Water Splitting

Abstract

Cleverly designing and synthesizing bifunctional electrocatalysts with high activity and exceptional stability for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) hold profound importance in the realm of renewable energy technologies. Here we demonstrated the fabrication of FeCoP hollow nanocubes by precisely controlling the oxidation-phosphorization processing on Prussian blue analogues. Owing to the robust electronic interaction and hollow structure, the obtained FeCoP material, when utilized for catalyzing HER and OER in a 1 M KOH solution, requires overpotentials of merely 74 mV and 219 mV to achieve 10 mA cm⁻², respectively. Importantly, when used as a bifunctional catalyst for overall water splitting, FeCoP can achieve a current density of 10 mA cm⁻² at a low cell voltage of only 1.58 V and exhibits impressive durability. After a prolonged test of 52 hours under a constant current density, there is no significant degradation performance decay. The current method offers a broader avenue for the controllable synthesis of phosphide electrocatalysts in practical applications.