Synthesis of Sponge‐Like Bi 2 O 3 by Using a Soft/Hard‐Combined Biomembrane Support System for Application as Supercapacitor

In this study, sponge‐like Bi 2 O 3 was successfully synthesized by a simple soft/hard‐combined biomembrane support system for the first time. The morphology and composition of the final products were characterized by SEM, TEM, XRD, and BET measurements. When the aging time is 20 min, the obtained Bi 2 O 3 based electrode exhibits a specific capacitance of 1103 F g –1 at 0.5 A g –1 and excellent rate capability (87.9 % capacitance retention from 0.5 A g –1 to 10 A g –1 ).