Surface selenium doped hollow heterostructure/defects Co-Fe sulfide nanoboxes for enhancing oxygen evolution reaction and supercapacitors

The strategy of constructing a three-dimensional hierarchically porous architecture with heterointerface and defects to rich the electrochemically active site, and rapid electron transfer has been considered as an effective strategy to achieve the excellent electrochemical performance in electrochemical energy storage and conversion. Herein, a Se-doped hollow heterostructure/defects Co-Fe sulfide (Se-(CoFe)S2) box has been developed via a facile sulfurization-selenization treatment of hollow Co-Fe Prussian blue analogues precursor. Remarkably, the abundant hierarchical macro-mesopores of hollow Se-(CoFe)S2 nanobox with excellent structural stability and unique electrical properties can not only effectively expose the electrochemically accessible active sites but also significantly improve the electrolyte transport and electron transfer, thus boosting electrochemical performances in oxygen evolution reaction (OER) and supercapacitors in alkaline media. For OER, the Se-(CoFe)S2 electrocatalyst shows a small overpotential of 281 mV at 10 mA cm−2 and a low Tafel slope of 51.8 mV dec−1 as well as high stability. Furthermore, it also shows good performance for supercapacitors, suggesting its great potential as an efficient electrode for sustainable energy applications. Superb properties highlight the great prospects of PBA-based derivatives in applications of energy storage and conversion.