Synthesis and characterization of erbium decorated V2CTx for water splitting properties

Abstract

The implication of two-dimensional (2D) MXene and their composites as catalysts for hydrogen (H2) and oxygen (O2) production represents an exciting area of research with great potential to revolutionize the field of catalysis. Herein, we demonstrated a method for surface modification of V2CTx MXene nanosheets (NSs) as an effective bifunctional nanocomposite electrocatalyst for water-splitting applications. This method involves the careful adsorption of the Erbium (Er) onto V2CTx NSs. Nanocomposites of Er@V2CTx were prepared by the sonication method. The Er@V2CTx in weight percentage ratio (0.12:1) nanocomposite (labeled as) achieved overpotentials of 174 mV vs. RHE (Reversible hydrogen electrode) and 370 mV (vs. OER) at the Tafel slope of 107 mV/dec for hydrogen evolution reaction (HER) and 131 mV/dec for the oxygen evolution reaction (OER) respectively, in 1.0 M KOH solution. The X-ray diffraction (XRD) analysis of pristine V2CTx and Er-decorated V2CTx (Er@V2CTx) nanocomposites revealed the presence of a 2D MXene structure with an increase in c-lattice parameter from 13.01 Å to 19.94 Å, indicating the successful adsorption of Er into MXene. Further, scanning electron microscopy (SEM) demonstrates that all samples have layered structures with evident sheet separation. The V2CTx MXene had strong electrical coupling, charge transfer, and contact, which resulted in substantially improved water-splitting performance, structural stability, and low charge transfer resistance, ultimately enhancing the catalyst's intrinsic activity.