Structural evolution of Ce[Fe(CN)6] and derived porous Fe-CeO2 with high performance for supercapacitor

Porous materials can be achieved using Metal–organic frameworks featuring various topological structures as templates. The structural evolution of Ce[Fe(CN)6] Prussian blue analogue (Ce-Fe PBA) was firstly controlled by adjusting reaction conditions at room temperature. Moreover, 3D porous Fe-CeO2 with rich oxygen vacancies were obtained by the pyrolysis of Ce-Fe PBA, which showed high performance for supercapacitor. In 1 M KOH, The as-prepared Fe-CeO2-500 electrode with the highest content of oxygen vacancies generated a high specific capacity (148 C/g at 0.5 A/g). In particular, an asymmetric supercapacitor of Fe-CeO2-500//activated carbon achieved an excellent energy storage density of 22.7 Wh/kg at a power density of 640 W/kg and excellent cycling stability with 74.5% of the capacity retention after 5000 cycles at 5 A/g. This exciting work not only offers a method to control the structural evolution of Ce-Fe PBA with uniform size, but also develops a porous material for high-performance supercapacitors.