# Food Waste-Derived Activated Carbon-Modified Nb2CTx MXene for Supercapacitor Applications

## TL;DR

This study explores using food waste-derived activated carbon to enhance the performance of MXene-based supercapacitor electrodes.

## Contribution

The novel use of food waste-derived activated carbon to optimize MXene's structure and electrochemical performance for supercapacitors.

## Key findings

- MXAC2 showed the highest specific capacitance of 651.84 F·g−1 at 5 mV·s−1.
- MXAC2 maintained 82.15% capacitance retention after 10,000 cycles.
- The composite exhibited low charge transfer resistance (0.023 Ω) and high coulombic efficiency.

## Abstract

In this study, the structural and electrochemical performance of Nb2CTx MXene-based composite electrodes modified with activated carbon (AC) derived from food waste was systematically investigated for supercapacitor applications. Three composites with Nb2CTx:AC mass ratios of 90:10 (MXAC1), 80:20 (MXAC2), and 70:30 (MXAC3) were prepared and comparatively evaluated. SEM/EDS, XRD, HR-TEM, XPS, and BET analyses revealed that, in the MXAC2 composite, activated carbon was homogeneously distributed between the MXene layers, effectively suppressing restacking and promoting the formation of a hierarchical micro/mesoporous structure. XPS results confirmed the preservation of the Nb–C framework and the enrichment of surface functional groups (–O, –OH, and –F). BET analysis demonstrated that MXAC2 possesses an optimized pore architecture that facilitates efficient ion diffusion. Electrochemical measurements revealed that the MXAC2 electrode exhibited the highest specific capacitance at all scan rates and current densities. At 5 mV·s−1, MXAC2 achieved a specific capacitance of 651.84 F·g−1 and maintained a substantial capacitance even at a high current density of 4 A·g−1. EIS analysis confirmed the very low charge transfer resistance (0.023 Ω) and enhanced capacitive behavior for MXAC2. Additionally, MXAC2 has high cycle stability, demonstrating 82.15% capacitive retention and 92.45% coulombic efficiency after 10000 cycles. These results indicate that food waste-derived AC-optimized Nb2CTx MXene composite materials are a strong candidate for sustainable and high-performance supercapacitor electrodes.