Dual-functional NiCo-MOF@La2O3@rGO interfaces driving energy storage and hydrogen evolution

초록

The development of next-generation supercapacitors demands electrode materials that unite high capacitance, rapid charge transport, and long-term stability while offering multifunctionality beyond storage. Here, a hierarchical NiCo-MOF@La2O3@rGO (NC-M@LO@rGO) composite is engineered to overcome the poor conductivity and limited durability of pristine MOFs. Oxygen-vacancy-rich La2O3 nanoparticles and conductive rGO sheets synergistically reconstruct the MOF framework into a mesoporous, defect-engineered network with abundant electroactive sites, enhanced OH- adsorption, and continuous electron pathways. Consequently, NC-M@LO@rGO achieves a specific capacitance of 3128 F g(-1) at 10 mV s(-1), retains 936.9 F g(-1) at 70 mV s(-1), and delivers 3595 C g(-1) at 1 A g(-1) with excellent rate performance. The asymmetric NC-M@LO@rGO//AC device exhibits an energy density of 45 Wh kg(-1) at 1600 W kg(-1), maintaining similar to 91.9% capacitance retention and 97.9% coulombic efficiency after 10,000 cycles. Beyond storage, the composite functions as an efficient hydrogen evolution electrocatalyst, requiring only 50 mV at 10 mA cm(-2), slightly above Pt/C, while sustaining outstanding durability. This dual functionality establishes a valuable design principle in which MOF-derived redox centers, oxide-mediated ion accelerators, and graphene conduction highways converge to yield scalable materials for integrated energy storage and conversion technologies.

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