Electrodeposition of nano- and micro-materials: Advancements in electrocatalysts for electrochemical applications

Electrodeposition is an essential technique for the fabrication of nanomaterials and thin films based on passing an electric current through a support electrode in contact with a solution containing a metal salt dissolved in it. Commonly referred to as ‘electroplating’ in industrial settings, this method is extensively used for developing a wide range of electrocatalytic materials due to its simplicity, versatility, cost-effectiveness, and efficiency. Despite its widespread use and growing popularity for electrocatalyst fabrication, electrodeposition processes are often misunderstood, and many research studies have not fully leveraged their potential due to a lack of understanding and optimisation of key aspects of the process; consequently, researchers may miss straightforward opportunities to maximise the performance and functionality of electrodeposited electrocatalysts, as small variations in the electrodeposition process parameters can have significant effects on their activity, selectivity and lifespan. To address these issues, the present review delves deeper into the fundamental principles of electrodeposition, explores the mechanisms of electrodeposited material growth and discusses potentiostatic, galvanostatic and pulse electrodeposition techniques in achieving uniform and high-quality films. Moreover, the review discusses how different operation parameters such as pH, temperature or current density influence the process itself and the properties of deposited materials and films. The use of electrodeposited materials as catalysts in various electrochemical applications such as

reduction, water splitting, pollutant removal and energy storage, among others, is also reviewed, along with a stimulating discussion on challenges faced by the research community and future opportunities for electrodeposition techniques in the area of electrocatalysis. By providing a comprehensive understanding of how process parameters affect the activity, selectivity, stability, and durability of electrodeposited electrocatalysts, this review underscores the importance of electrodeposition in advancing sustainable and efficient energy solutions.