Bipolar Electrodeposition of Bimetallic Alloy (Au-Ag) Gradient: Formation, Characterization and Application

Abstract

Bipolar electrochemistry is an attention-grabbing conception for high throughput screening practices due to the capability to make gradients in a variety of materials and their properties, such as composition, particle size, or dopant levels, among many others. The main key advantages of the method are the ability to test, create or modify materials without the need for a direct electrical connection. This whole work is based on bipolar electrochemistry. In this thesis, my first chapter described an introduction of electrodeposition processes. The basic principles of bipolar electrochemistry are also presented in this chapter. The formation of metal gradients and its application also included in this chapter. Chapter 2 describes the characterization of Au-Ag alloy gradient formed by bipolar electrodeposition on a stainless steel bipolar electrode, using SEM/EDX and its screening for the electrocatalytic activity towards 4-nitrothiophenol (4-NTP) reduction using Raman spectroelectrochemistry. Chapter 3 contains the synthesis of one and two dimensional Au-Ag alloy gradients using bipolar electrodeposition method. The alloy gradients were characterized using SEM/EDX. Confocal Raman microscopy was employed to determine the optimum alloy composition that resulted in the maximum surface enhanced Raman scattering (SERS) intensity. Chapter 4 is the summary of my research work.