Hierarchical 2D MnO₂@1D mesoporous NiTiO₃ core-shell hybrid structures for high-performance supercapattery electrodes: Theoretical and experimental investigations

Novel hybrid core–shell electrodes of 2D and 1D nanomaterials have the ability to effectively address the relatively lower specific energy of supercapacitors. Herein, we report the utilization of the core–shell structure of hierarchical 2D Manganese Dioxide (MnO₂) nanoflakes and 1D Nickel Titanate (NiTiO₃) (NTO) mesoporous rods as an efficient supercapacitor electrode providing an enormous surface area and more pathways for OH^– ions diffusion. The two-step-chemically processed hybrid porous core–shell hetero-architecture of MnO₂@NTO delivers a specific capacitance of 1054.7 F/g, specific power of 11879.87 W/kg, and specific energy of 36.23 Wh/kg. Furthermore, 85.3 % retention in capacitance is perceived after 5000 cycles without degradation in the surface morphological features. Complementary first principles density functional theory (DFT) calculations reveal synergistic interaction of MnO₂ with NTO in the MnO₂@NTO heterostructure, which improves the electrical conductivity.