Prussian Blue Analogues–Derived CoFe–B Nanocubes with Increased Specific Surface Area and Modulated Electronic Structure as Enhanced Oxygen Evolution Electrocatalysts

Abstract

Questing for efficient and inexpensive catalysts for electrochemical water splitting is vital for energy conversion and storage. Herein, Prussian blue analogues (PBA)‐derived CoFe‐based nanomaterials with increased specific surface area and abundant catalytic active sites are utilized as efficient and durable electrocatalysts for oxygen evolution reaction (OER). Due to the adjustable chemical conformation and controllable 3D morphology, CoFe–B nanocubes exhibit an ultrathin nanosheets–wrapped nanocube structure with excellent electrocatalytic performance and remarkable reaction kinetics in 1.0 m KOH aqueous solution. In addition, CoFe–B nanocubes cost overpotentials of 261 and 338 mV at corresponding current densities of 10 and 200 mA cm−2, respectively, with small Tafel slope of 61 mV dec−1 for OER, which displays higher catalytic capability than the reported commercial RuO2. The outstanding electrocatalytic performance can be mainly attributed to the unique ultrathin nanosheets–wrapped nanocube structure which is generated from calcination. This work not only provides a new way for the application of PBA but also obtains an alternative for efficient electrocatalysis.