In situ synthesis of MXene@Iron oxide nanoparticle composites via pulsed laser ablation in liquid applied for electrochemical H₂O₂ reduction

We propose to circumvent the lack of intrinsic magnetism in MXenes by in situ decorating the samples with magnetic nanoparticles during laser ablation in liquid by deposition of iron species on three types of MXenes (nanocomposites). The basic properties of such nanocomposites were characterized by a number of techniques including Scanning Electron Microscopy (SEM), Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS), electrochemical investigation and the optical Faraday effect. The results indicate significant differences in the content of Fe species deposited on MXenes (Ti₃C₂T_x; Nb₂CT_x and Nb₄C₃T_x) and the amount of Fe species deposited on MXenes is triggered by the density of plasmons present within MXenes. Moreover, we confimed a correlation between the capability of MXene-based Fe nanocomposites to electrochemically reduce hydrogen peroxide and electrochemical activity of Fe species present on MXenes. The highest electrochemical current density obtained for H₂O₂ reduction was obtained on the Ti₃C₂T_x MXene-based Fe nanocomposite with the value of 4399 µA cm⁻². We further discuss how to improve the current density obtained for H₂O₂ reduction on the other MXene-based Fe nanocomposites (Nb₂CT_x and Nb₄C₃T_x) using alternative synthesis protocols.