Prussian blue analogues derived binary nickel-cobalt selenide for enhanced pseudocapacitance and oxygen evolution reaction

Abstract

Prussian blue analogue-derivatives with unique structures have been widely used as electrode materials for electrochemical energy storage and catalysis. In this work, we prepare CoSe2 and (Ni,Co)Se2 nanocubes by selenylation prussian blue analogues in argon. The (Ni,Co)Se2 nanocubes exhibits a high specific capacitance of 778 F g−1 at 1 A g−1, which is much higher than CoSe2 nanocubes. Except for excellent pseudocapacitance performance, the (Ni,Co)Se2 nanocubes show an outstanding electrochemical catalysis ability for the oxygen evolution reaction that achieve a current density of 10 mA cm−2 only need a low overpotential of 278 mV and exhibits a small Tafel slope. This work successfully add two materials to the growing category of MOF-derivatives and combine the energy storage and conversion, which have a promising potential for further practical application.