Interfacial Mn-Ni selenide/ Ti2NbC2Tx MXene heterostructures for integrated water splitting and supercapacitive energy storage

초록

Green hydrogen production via electrocatalytic water splitting offers a sustainable pathway toward zero-carbon energy systems. However, sluggish charge-transfer kinetics, poor stability, and high costs of electrocatalysts limit practical applications. To address these challenges, we anchor a manganese-nickel (Mn-Ni) selenide onto Ti2NbC2Tx MXene via a solvothermal approach, integrating MXene's intrinsic conductivity with the redox-active Mn/Ni sites. The resulting hybrid exhibits excellent bifunctional activity, achieving 10 mA cm-2 at low over-potentials of 173 and 232 mV for HER and OER, respectively, outperforming RuO2. The full water-splitting cell reaches 100 mA cm-2 at 1.74 V while demonstrating robust durability over 100 h. Beyond electrocatalysis, as a supercapacitor electrode, the hybrid delivers a high specific capacitance of 2106 F g-1 at 1 A g-1, and the symmetric device achieves an energy density of 43.4 Wh kg-1 at 750 W kg-1, highlighting its exceptional energy storage performance. This study provides a rational strategy for designing bimetallic MXene-selenide hybrid heterostructures as multifunctional materials for integrated energy conversion and storage applications.

키워드