Hierarchical MXene/ACF/Ni-MOF ternary composites: Rational design and enhanced supercapacitive performance

Composite nanomaterials MXene/ACF/Ni3(HITP)2 with a three-dimensional network structure were synthesized using two-dimensional MXene nanosheets and one-dimensional structured acidified activated carbon fiber (ACF) as substrates. This design aims to enhance the specific surface area of the composites, expose more active sites, and provide efficient electron transport channels, thereby facilitating rapid ion transfer. MXene/ACF/Ni3(HITP)2 composites exhibit superior specific capacitance and multiplicity properties compared with ACF/Ni3(HITP)2 composites. In particular, the MXene/ACF/Ni3(HITP)2 composites exhibit a specific capacity of 159.6 F g-1 at a current density of 0.5 A g-1, surpassing the 125 F g-1 observed for ACF/Ni3(HITP)2 composites under identical conditions. Symmetric supercapacitor devices assembled with MXene/ACF/Ni3(HITP)2 composites have a specific capacitance of 41.2 F g-1 at a current density of 0.5 A g-1. Notably, after 5000 cycles at 3 A g-1, the initial capacitance retention remains above 93.8%. Beyond delivering high-performance electrodes, this approach effectively enhances the construction of electrode materials with elevated electrochemical activity and stable geometries.