Porous WO3@CuO composites derived from polyoxometalates@metal organic frameworks for supercapacitor

This work presents a novel strategy to prepare homogeneous and porous WO3@CuO composites by employing a POMs@MOFs template (POMs = polyoxometalates, MOFs = metal organic frameworks), in which the W-based POMs are incorporated into Cu-based MOFs as secondary building units. The porous structure of the composites can provide the sufficient pathways for ion transport and electron diffusion in supercapacitor. In addition, the doping of WO3 to CuO contributes to the excellent electrochemical performance of the composite electrode, which exhibits a specific capacitance of 284 F g−1 at a current density of 1 A g−1, much higher than pure CuO electrode (48 F g−1). Moreover, the composite material has shown longer cycle life of 85.2% capacitance retention over 1500 cycles.