Nitride based 2D MXene and thin films optoelectronic electrochemical and anti corrosion studies for energy storage applications

Abstract

The development of advanced materials for electrochemical energy storage and corrosionresistant applications has garnered substantial research interest, particularly with the emergence of two-dimensional (2D) MXenes and transition metal nitride thin films. This thesis explores the synthesis, structural, optical characterisation, and electrochemical evaluation of nitride-based thin films and MXene composites engineered through various physical and chemical methods to enhance their functionality for supercapacitor and anti-corrosion applications. Initially, TiN/Ti multilayer thin films with varying interlayer thicknesses were fabricated using DC magnetron sputtering to investigate the temperature-dependent diffusion behaviour of nitrogen and assess their electrochemical performance. The AFM analysis confirmed a surface roughness of ~4.91 nm. Secondary Ion Mass Spectroscopy (SIMS) studies revealed significant Nand#8322; migration at 698 K, resulting in the formation of Tiand#8322;N MXene phases, with an estimated diffusivity of ~10and#8315;¹and#8312; m²/s. Photoluminescence spectra indicated the presence of Ti, N, and O defect states, while electrochemical measurements showed a notable areal capacitance (Cand#8336;) ranging from 56.3 250 mF/cm² and energy densities (E) between 0.27 1.37 mWh/cm². The multilayer configurations exhibited high conductivity and capacitive retention (~85.4%) with a coulombic efficiency reaching up to 650%. A diffusion-controlled mechanism dominated the TiN2.5nm/Ti2.5nm multilayer thin films, while capacitive effects were prominent in the TiN10nm/Ti10nm configuration. Electrochemical impedance spectroscopy (EIS) and Tafel analyses confirmed the superior charge transfer and corrosion resistance properties of the thin films, establishing their potential as viable anode materials in energy storage devices. To study composition-dependent properties, Tiand#8321;and#8331;and#8339;Vand#8339;N (0 and#8804; x and#8804; 1) thin films were deposited (~150 nm thickness) and characterised.