Investigating the impact of various etching agents on Ti3C2Tx MXene synthesis for electrochemical energy conversion

Abstract

MXenes represent a revolutionary class of two-dimensional (2D) materials that have garnered significant attention due to their unique properties, including excellent electrical conductivity, and remarkable mechanical strength. This study investigates the influence of different etching agents on the synthesis of MXenes for electrochemical energy conversion applications, particularly in methanol oxidation reactions (MOR). Morphological characterization, particle distribution and sizing, elemental analysis, and surface chemistry assessments were conducted using field emission scanning electron microscopy (FESEM), elemental mapping, transmission electron microscopy (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). Electrochemical techniques such as cyclic voltammetry (CV), electrochemical active surface area (ECSA), Tafel analysis, electrochemical impedance spectroscopy (EIS), and long-term stability assessment were employed. The study reveals that PtRu/MXene synthesized with the FeF₃/HCl etching route exhibits the highest ECSA value and peak current density, being 12.3 times and 3.63 times higher than those achieved via the LiF/HCl etching route. The kinetic rate, tolerance to catalyst poisoning and long-term stability also show the better results for this etching route. These findings suggest promising potential for PtRu/MXene_FeF₃/HCl as an effective anodic electrocatalyst in direct methanol fuel cell (DMFC) applications.