MOF-derived MIL-53(Al)@KTi2(PO4)3@rGO ternary heterostructure as a bifunctional electrode for high-performance hybrid supercapacitors and hydrogen evolution

초록

The rising requirement of sustainable and multifunctional electrodes for energy storage and production has stimulated significant interest in advanced electrode architectures. In this study, a MIL-53(Al)@KTi2(PO4)(3)@rGO composite was fabricated by means of combined hydrothermal and modified Hummers approach. The composite was rationally designed by integrating the MIL-53(Al), the favorable ionic transport characteristics of NASICONtype KT2(PO4)(3), and the highly conductive network of rGO, there by promoting efficient charge and ion transport. Electrochemical evaluation in a three-electrode cell demonstrated a high specific capacity of 1189.23C g(-1). When assembled into a two-electrode supercapacitor device, the material delivered an energy density of 45 Wh kg(-1) at a power density of 2773 W kg(-1). The device also maintained 92% of its initial capacity with a Coulombic efficiency of 97% after 10,000 consecutive charge-discharge cycles, indicating strong electrochemical durability. In addition to its energy storage performance, the MIL-53(Al)@KT2(PO4)(3)@rGO electrode demonstrated promising catalytic activity for the hydrogen evolution reaction, requiring only 46 mV overpotential to achieve the targeted current density and exhibiting a Tafel slope of 49 mV dec(-1). These results highlight the synergistic contribution of the MOF, NASICON phosphate, and rGO components and establish MIL53(Al)@KT2(PO4)(3)@rGO as a promising multifunctional platform for advanced supercapacitor systems and electrocatalytic hydrogen production.

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