Rationally designed CeO2 decorated Ti3C2 MXene interface for efficient water splitting and enhanced supercapacitor performance

Abstract

MXenes serve as competent electrodes for applications such as energy storage and conversion owing to their unique characteristics, which include substantial surface area, excellent conductivity, abundant surface-terminating groups, and high hydrophilicity. However, MXene nanosheets exhibit a pronounced tendency to restack via Van der Waals force, hindering the active sites and resulting in sluggish electronic and ionic kinetics. This phenomenon limits the capabilities, processability, and overall performance of MXene. In this study, CeO2 is utilized as an interlayer spacer for the Ti3C2 MXene substrate, providing a promising noble metal-free multifunctional electrode. The Ti3C2/CeO2 composite, synthesized via the hydrothermal method, efficiently mitigates restacking while exhibiting excellent conductivity, substantial surface area, and enhanced kinetics. The as-synthesized catalysts undergo diverse physiochemical characterizations and electrochemical measurements to understand their properties and potential multiapplications. The fabricated electrode material, Ti3C2/CeO2, shows excellent specific capacitance of 1908.5 Fg−1 at 1 Ag−1 in a three-electrode setup using 3 M KOH as electrolyte. It has a capacitive retention of 91% even after 4000 cycles. Besides, Ti3C2/CeO2 also functions as a proficient electrode material for overall water splitting, having a lower overpotential of 178 mV and 350 mV for hydrogen and oxygen evolution reactions, respectively, at a current density of 10 mAcm−2. It also displays a lower cell voltage of 1.78 V to obtain a current density of 10 mAcm−2. This study introduces the multi applications of a well-designed interface between Ti3C2 layers and CeO2 within the realm of electrochemical energy storage and conversion.