Prussian blue analogue metal organic framework-derived CoSe2 nanoboxes for highly efficient oxygen evolution reaction

Hollow nanoparticles with tailored shell structures have been attractive for electrochemical energy storage applications. CoSe2 nanoboxes (NBs) were synthesized successfully using Co-Prussian blue analogue (PBA) metal organic framework (MOF) as a template. Co-PBA NBs were obtained by etching the cube-shaped crystals of Co-PBA with ammonia. Subsequent selenization of Co-PBA NBs afforded CoSe2 NBs. Due to the hollow and conductive nature, the CoSe2 NBs provided excellent electrocatalytic activity for oxygen evolution reaction (OER). In 1 M KOH aqueous solution, CoSe2 NBs delivered overpotential of 335 mV at a current density of 10 mA cm−2, Tafel slop of 54.2 mV dec−1, and good cycling stability, suggesting possibility of being used as a electrochemical catalyst for alkaline fuel cells.