The rational design of bifunctional MOF-ZnFe2O4 hollow sphere-based nanocomposites for ultra-efficient electrochemical oxygen evolution reaction and high-performance symmetric supercapacitor electrodes

초록

Supercapacitors have emerged as versatile energy storage devices, valued for their rapid charge-discharge capabilities and long cycle life. Concurrently, efficient electrocatalysts are essential for promoting the oxygen evolution reaction (OER) in sustainable energy applications. Inevitably, this study explores the integration of a Cobalt-Nickel (Co/Ni) based metal-organic framework [CoNi((mu 3-tp)2(mu 2-py)2 or CNTP] with ZnFe2O4 hollow spheres (ZHS) to create innovative CNTP/ZHS nanocomposites tailored for supercapacitor and electrocatalytic OER applications. Different weight percentages of CNTP/ZHS nanocomposites were synthesized through a facile and scalable method, and their electrochemical performance was rigorously assessed. Electrochemical characterization revealed that a 40 wt percentage CNTP/ZHS (40-CNTP/ZHS) electrode demonstrated a very high specific capacitance of 1519.2 Fg- 1 at 1 Ag- 1 and retained 92.6 % of its specific capacitance after 10000 cycles. Moreover, it delivered remarkably high specific capacitance (447.2 Fg-1) and energy density (62.1 WhKg-1) along with outstanding cyclic stability (97.5 % after 5000 galvanostatic charge-discharge cycles). It also exhibited excellent OER activity, with a very low overpotential (207 mV to attain a current density of 10 mAcm-2), a small Tafel slope (66.5 mVdec-1), and high stability over 2000 cyclic voltammetry cycles. These characteristics underscore the significant potential of renewable energy technologies, particularly for water electrolysis and sustainable energy conversion.

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