Scalable one-pot bacteria-templating synthesis route toward hierarchical, porous-Co₃O₄ superstructures for supercapacitor electrodes

Template-driven strategy has been widely used to synthesize inorganic nano/micro materials. Here, we used a bottom-up controlled synthesis route to develop a powerful solution-based method of fabricating three-dimensional (3D), hierarchical, porous-Co₃O₄ superstructures that exhibit the morphology of flower-like microspheres (hereafter, RT-Co₃O ₄). The gram-scale RT-Co₃O₄ was facilely prepared using one-pot synthesis with bacterial templating at room temperature. Large-surface-area RT-Co₃O₄ also has a noticeable pseudocapacitive performance because of its high mass loading per area (~10 mg cm^-2), indicating a high capacitance of 214 F g^-1 (2.04 F cm^-2) at 2 Ag^-1 (19.02 mAcm^-2), a Coulombic efficiency averaging over 95%, and an excellent cycling stability that shows a capacitance retention of about 95% after 4,000 cycles.