Dopamine-Assisted Hydrothermal Synthesis of Porous Co3O4 Spherical Nanostructures for High-Performance Supercapacitor Applications

초록

Porous cobalt oxide (Co3O4) nanostructures were synthesized using a dopamine-assisted hydrothermal method followed by calcination to improve their electrochemical performance for supercapacitors. In this process, dopamine served as both a chelating and structure-directing agent, guiding the nucleation and growth of cobalt precursors into uniform, porous, sphere-like structures. The optimized D2.0-Co3O4 sample, consisting of interconnected nanoparticles, showed a large surface area of 90.25 m2 g-1 and open-pore channels, facilitating efficient ion diffusion and charge transport. Calcination at 400 degrees C finished the phase transition of cobalt hydroxide intermediates into crystalline Co3O4. Comparative studies with D1.0-Co3O4 and dopamine-free Co3O4 revealed that the dopamine concentration significantly affects the structural and electrochemical properties of the final material. The D2.0-Co3O4 electrode exhibited exceptional pseudocapacitive behavior, achieving a high specific capacitance of 930.2 F g-1 at 1 A g-1, a 99% rate capability, and outstanding cycling stability, retaining 96% of its capacitance after 3800 cycles. The improved performance results from the optimized porosity and surface features of D2.0-Co3O4. Therefore, the dopamine-assisted synthesis offers an effective approach for designing structurally controlled transition metal oxides for high-performance energy storage devices.

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