Dottorato in MODELLI MATEMATICI PER L'INGEGNERIA, ELETTROMAGNETISMO E
NANOSCIENZE

Titolo della tesi: “Fabrication and characterization of 2D MXene nanosheets based novel energy storage devices."

This dissertation advances the synthesis and functionalization of MXene materials, focusing on Ti3AlC2 and V2AlC phases for energy storage applications. This study presents new low-cost synthesis methods for exfoliating multilayer MXene materials through selective etching with aqueous hydrofluoric acid and delamination by using different organic base treatment. The etching process creates accessible interlayer spaces, providing numerous active sites for ion storage, crucial for enhancing electrochemical performance. For Ti3AlC2 MAX Phase, thin Ti3C2Tx MXene layers were successfully fabricated using TMAOH treatment at room temperature, avoiding ultra-sonication. This method not only removed aluminium but also reduced fluorine on the MXene surface, enhancing its suitability as an electrode material. Intercalating TMA+ ions into Ti3C2Tx MXene enlarges interlayer spacing and reduces fluorine content, significantly improving the material's quality for energy storage applications. The hexagonal crystal structure and composition of the MXene were characterized using various techniques. X-ray Photoelectrons Spectroscopy, Raman spectroscopy and electrochemical analysis showed that these treatments significantly altered the MXene's structure and surface chemistry, improving battery performance for lithium, sodium, and potassium ions. For the V2AlC phase, a new V2CTx MXene was developed using low temperature etching and exfoliation. This process effectively removed aluminium and incorporated TBA+ ions, creating defects that improved the MXene's electrochemical properties. SEM and EDX analyses confirmed the successful formation of V2CTx layers, while Raman spectroscopy and cyclic voltammetry demonstrated high specific capacitance and enhanced performance, making it a promising material for energy storage mechanism in double layer supercapacitors. Overall, this research provides improved methods for synthesizing and treating MXenes, leading to better performance in electronic and energy storage applications.