Facile synthesis of high-performance free-standing hierarchically porous NiO/Bi@Bi2O3 hybrid electrode for supercapacitors

By tactfully utilizing the different chemical characteristics of Bi and Ni element in the electrodeposition process, this work successfully designs a novel free-standing NiO/Bi@Bi₂O₃ hybrid electrode with dual electroactive components (NiO and Bi@Bi₂O₃) and hierarchically porous structure. After co-electrodeposition, the porous Bi metal as a conductive skeleton can effectively improve the electrical conductivity of the electrode. Moreover, Bi₂O₃ and NiO have synergistic effects by modifying the electronic structure. The newly developed bimetallic NiO/Bi@Bi₂O₃ hybrid electrode exhibits high volumetric capacitance value of 1166.67 F cm⁻³, which is attributed to the dual advantages of structure and composition. This work provides a new idea for the design of high-performance transition metal oxide-based electrodes.