Heterostructured Co-NiSe₂ Nanorods on MXene Nanosheets as Synergistic Electrode Material for Supercapacitor

MXenes, a class of two-dimensional (2D) materials, have gathered significant attention as excellent electrode materials for various energy applications owing to their remarkable properties such as superior metallic conductivity, abundant surface functionality, high electrical conductivity, hydrophilicity, abundance of surface active sites, enormous cycle life, and ordered lamellar structure. In this study, we present the heterostructured growth of bimetallic Co-NiSe₂ on MXene via a simple hydrothermal method. The resulting hybrid structure of Co-NiSe₂ exhibits nanorod-like morphology wrapped around MXene sheets. When evaluated as an electrode material for supercapacitors, the Co-NiSe₂/MXene composite demonstrates enhanced feasibility, displaying relatively high specific surface area and electrical conductivity, thus exhibiting excellent electrochemical performance. Specifically, the Co-NiSe₂/MXene composite exhibits a high specific capacitance of 1394.8 F·g^-1 at a current density of 1 A·g^-1. Furthermore, the synergetic hybrid material can deliver a high energy density of 20 Wh·kg^-1 at a power density of 684 W·kg^-1. Importantly, the Co-NiSe₂/MXene material exhibits good rate performance and cycle stability, showcasing its potential for advanced energy storage applications.