New insights in nanoelectrodeposition: An electrochemical aggregative growth mechanism

Abstract

Supported nanostructures represent the cornerstone for numerous applications in different fields such as electrocatalysis (fuel cells) or electroanalysis (sensors). In contrast to other methods, electrochemical deposition allows the growth of the nanostructures directly on the final support, improving the electron pathway within the substrate, nanostructure, and electrolyte. However, despite the increasing number of publications in the field, the early stages of electrochemical nanocrystal formation are still under discussion. In this chapter, we first provide a survey on the traditional approaches to study the early stages of electrochemical nucleation and growth, together with the classical theories used to understand them. Next, we describe our most recent findings which have led to reformulate the Volmer-Weber island growth mechanism into an electrochemical aggregative growth mechanism which mimics the atomistic processes of the early stages of thin-film growth by considering nanoclusters of few nm as building blocks instead of single atoms. We prove that the early stages of nanoelectrodeposition are strongly affected by nanocluster selflimiting growth, surface diffusion, aggregation, and coalescence.