Oxalate-assisted synthesis of MnCo2O4 nanoparticles on layered MXene (Ti3C2Tx) for supercapacitor application

Abstract

The synthesis of MnCo₂O₄/Ti₃C₂Tx composite powders was achieved through a hydrothermal method facilitated by oxalate assistance. To assess the influence of MXene levels (0, 25, and 50 wt%) on microstructure, structure, and electrochemical performance, modern characterization methods were applied in this study. The mixed manganese‑cobalt oxalates were precipitated on the layered MXene by adding a proper amount of oxalic acid to the Nitride solution. The MnCo₂O₄ nanoparticles were then crystallized by heat treatment at 450 °C for one hour in a nitrogen gas atmosphere. The pristine MnCo₂O₄ had a columnar-like morphology, which was transformed into a fine particulate microstructure by combining with MXene. These pristine MnCo₂O₄ powders indicated a higher specific capacitance of 1116 F g⁻¹, significantly exceeding the 640.5 Fg⁻¹ recorded for the pristine layered MXene. The Incorporation of 25 wt% layered MXene enhanced the specific capacitance to a remarkable 1500 Fg⁻¹, attributed to its finer microstructure. Under a current rate of 1 Ag⁻¹, the capacitor composed of MnCo₂O₄-25 wt% MXene//activated carbon achieved an energy density of 43.5 Wh kg⁻¹ at a power density of 1411 W kg⁻¹.