Microwave-Assisted Synthesis of Few-Layer Ti3C2Tx Loaded with Ni0.5Co0.5Se2 Nanospheres for High-Performance Supercapacitors.

Abstract

Transition metal selenides have high theoretical capacities, making them attractive candidates for energy storage applications. Here, using the microwave-absorbing properties of the materials, we designed a simple and efficient microwave-assisted synthesis method to produce a composite made of nanospheres Ni0.5Co0.5Se2 (NCSe) and highly conductive, stable Ti3C2Tx MXene. The Ni0.5Co0.5Se2/Ti3C2Tx composites are characterized via scanning electron microscopy, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. The findings indicate that 3D Ni0.5Co0.5Se2 bimetallic selenide nanospheres were uniformly loaded within the few-layer Ti3C2Tx MXene wrapper in a short period. The optimal NCSe/Ti3C2Tx-2 electrode can demonstrate a specific capacitance of 752.4 F g-1 at 1 A g-1. Furthermore, the asymmetric supercapacitor combined with activated carbon maintains a capacitance retention of 110% even after 5000 cycles. The method of directly growing active substances on few-layer Ti3C2Tx MXene will provide inspiration for the manufacture of high-pseudocapacitance supercapacitors.