Ternary (molybdenum disulfide/graphene)/carbon nanotube nanocomposites assembled via a facile colloidal electrostatic path as electrocatalysts for the oxygen reduction reaction: Composition and nitrogen-doping play a key role in their performance

Marcos Rocha; Bárbara Abreu; Marta S Nunes; Cristina Freire; Eduardo F Marques

doi:10.1016/j.jcis.2024.03.014

Ternary (molybdenum disulfide/graphene)/carbon nanotube nanocomposites assembled via a facile colloidal electrostatic path as electrocatalysts for the oxygen reduction reaction: Composition and nitrogen-doping play a key role in their performance

J Colloid Interface Sci. 2024 Jun 15:664:1056-1068. doi: 10.1016/j.jcis.2024.03.014. Epub 2024 Mar 6.

Authors

Marcos Rocha¹, Bárbara Abreu¹, Marta S Nunes², Cristina Freire³, Eduardo F Marques⁴

Affiliations

¹ CIQUP - Centro de Investigação em Química da Universidade do Porto, Institute of Molecular Sciences (IMS), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, Porto 4169-007, Portugal; REQUIMTE-LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, Porto 4169-007, Portugal.
² REQUIMTE-LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, Porto 4169-007, Portugal. Electronic address: marta.nunes@fc.up.pt.
³ REQUIMTE-LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, Porto 4169-007, Portugal.
⁴ CIQUP - Centro de Investigação em Química da Universidade do Porto, Institute of Molecular Sciences (IMS), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, Porto 4169-007, Portugal. Electronic address: efmarque@fc.up.pt.

PMID: 38531183
DOI: 10.1016/j.jcis.2024.03.014

Abstract

Nanocomposites have garnered attention for their potential as catalysts in electrochemical reactions vital for technologies like fuel cells, water splitting, and metal-air batteries. This work focuses on developing three-dimensional (3D) nanocomposites through aqueous phase exfoliation, non-covalent functionalization of building blocks with surfactants and polymers, and electrostatic interactions in solution leading to the nanocomposites assembly and organization. By combining molybdenum disulfide (MoS₂) layers with graphene nanoplatelets (GnPs) to form a binary 2D composite (MoS₂/GnP), and subsequently incorporating multiwalled carbon nanotubes (MWNTs) to create ternary 3D composites, we explore their potential as catalysts for the oxygen reduction reaction (ORR) critical in fuel cells. Characterization techniques such as X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction elucidate material composition and structure. Our electrochemical studies reveal insights into the kinetics of the reactions and structure-activity relationships. Both the (MoS₂/GnP)-to-MWNT mass ratio and nitrogen-doping of GnPs (N-GnPs) play a key role on the electrocatalytic ORR performance. Notably, the (MoS₂/N-GnP)/MWNT material, with a 3:1 mass ratio, exhibits the most effective ORR activity. All catalysts demonstrate good long-term stability and methanol crossover tolerance. This facile fabrication method and observed trends offer avenues for optimizing composite electrocatalysts further.

Keywords: Carbon and layered nanomaterials; Electrocatalysts; Fuel cells; Nanocomposites; Oxygen reduction reaction; Surfactants.