A review on poly(amidoamine) dendrimer encapsulated nanoparticles synthesis and usage in energy conversion and storage applications

Abstract

A review on poly(amidoamine) dendrimer encapsulated nanoparticles synthesis and usage in energy conversion and storage applications. • The Dend-NPs for electrochemical energy conversion and storage is reviewed. • Synthesis methods to prepare active and durable Dend-NPs are summarized. • The best practice and beforehand knowledge of Dend-NPs are recommended. • The electrocatalytic activity of Dend-NPs towards multiple reactions are discussed. • The reasons for high performance in multiple energy systems are highlighted. The direction of this review is concentrating on the development of poly(amidoamine) (PAMAM) dendrimer encapsulated metal nanoparticles (NPs), so-called Dend-NPs as catalysts in the field of electrochemical energy conversion and storage. To date, Dend-NPs have been pointed out as well-organized and effective catalysts in the most popular electrochemical technologies, such as fuel cells, batteries, supercapacitors and water electrolyzers. Different strategies and technological progresses targeting efficient power and energy productions with excellent durability and performance retentions in such systems are emphasized. Dend-NPs action in electrochemical energy systems thrived by cathodic catalytic reactions, particularly, hydrogen evolution reaction (HER) in electrolyzers and oxygen reduction reaction (ORR) in fuel cells, and electrochemical (Faradaic and non-Faradaic) processes in batteries and supercapacitors are summarized. The metal NPs produced within the dendrimer by various approaches, conditions for obtaining zero-valent metals and synthesis methods for different types of metal NPs are discussed. Advancing knowledge of Dend-NPs synthesis, difficulties and their solutions and the best practice recommended for readers are explained in brief. Besides, stability, role of dendrimer, generation effects, terminal group effects and mechanisms to encapsulate each transition and precious metal NPs such as copper (Cu), nickel (Ni), platinum (Pt), palladium (Pd), silver (Ag), gold (Au) and bimetallic within the cavity of PAMAM dendrimers are highlighted. Moreover, PAMAM dendrimer and its generation are classified bearing in mind their viable use in energy technologies and applications where possible.