Development of nanostructured-graphene-supported silver nanoparticles as catalysts for electroreduction of oxygen in alkaline electrolyte

TL;DR

This study develops a simple, efficient method to synthesize silver nanoparticles supported on various graphene-based materials, demonstrating enhanced catalytic activity for oxygen reduction in alkaline electrolytes, especially with SiO2-doted reduced-graphene-oxide.

Contribution

It introduces a single-step synthesis technique for silver nanoparticles on graphene supports, optimizing catalytic performance for oxygen reduction reactions.

Findings

SiO2-doted reduced-graphene-oxide supported silver nanoparticles show superior ORR activity.

The hybrid material achieves nearly 4-electron transfer, indicating efficient oxygen reduction.

The synthesis method ensures 100% utilization of silver precursor.

Abstract

Here we develop a class off face centred cubic structure of metallic silver nanocrystals, to enable high ORR activity process. Silver nanoparticles deposited within different carbon supports: carboxylated-graphene, SiO2-doted reduced- graphene-oxide (Gr/SiO2) and reduced-graphene-oxide (Gr) were prepared. The reduction of silver ions and the formation of silver nanoparticles deposited within graphene-type supports have been assessed by UV-Vis spectroscopy and was confirmed by XRD studies. The major advantage of the proposed chemical synthetic method is the integration of the superb properties of both silver nanoparticles and graphene supports in a single-step synthesis with a 100% usage of the silver precursor (AgNO3). The choice of the carbon support strongly affected catalytic activity of the resulting Ag nanoparticles towards oxygen electroreduction in alkaline medium. We show that SiO2-doted reduced- graphene-oxide supported silver nanoparticles display significantly enhanced catalytic activity towards the oxygen reduction reaction (ORR) in alkaline solutions compared to the silver nanoparticles immobilized within carboxylated-graphene support and chemically reduced graphene oxide (Gr). Moreover under RRDE conditions the hybrid material based on SiO2-doted reduced- graphene-oxide supported silver nanoparticles displays the most impressive electrocatalytic performance toward ORR and shows the highest number of exchanged electrons (n) ranging from 3.96 to 3.998 when compared to the silver nanoparticles immobilized within carboxylated-graphene support (3.90-3.994) and reduced-graphene-oxide (Gr) supported silver nanoparticles (3.88-3.991).