Nanocomposites Prepared from Carbon Nanotubes and the Transition Metal Dichalcogenides WS2 and MoS2 via Surfactant-Assisted Dispersions as Electrocatalysts for Oxygen Reactions

• Tipo: Artigo em Revista Científica Internacional
• Data: 2021

Autores

Ferreira, P (Autor) Outra; Abreu, B (Autor) FCUP; Cristina Freire (Autor) FCUP; Diana M Fernandes (Autor) FCUP; Eduardo F Marques (Autor) FCUP

Revista

Título: Materials

Vol. 14 Nº 19

Páginas: 1-16

ISSN: 1996-1944

Editora: MDPI

Indexação

ISI Web of Knowledge - 11 Citações

Scopus - 11 Citações

Outras Informações

ID Authenticus: P-00T-FD9

DOI: 10.3390/ma14040896

Abstract (EN): Fuel cells are emerging devices as clean and renewable energy sources, provided their efficiency is increased. In this work, we prepared nanocomposites based on multiwalled carbon nanotubes (MWNTs) and transition metal dichalcogenides (TMDs), namely WS2 and MoS2, and evaluated their performance as electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR), relevant to fuel cells. The one- and two-dimensional (1D and 2D) building blocks were initially exfoliated and non-covalently functionalized by surfactants of opposite charge in aqueous media (tetradecyltrimethylammonium bromide, TTAB, for the nanotubes and sodium cholate, SC, for the dichalcogenides), and thereafter, the three-dimensional (3D) MoS2@MWNT and WS2@MWNT composites were assembled via surfactant-mediated electrostatic interactions. The nanocomposites were characterized by scanning electron microscopy (SEM) and structural differences were found. WS2@MWNT and MoS2@MWNT show moderate ORR performance with potential onsets of 0.71 and 0.73 V vs. RHE respectively, and diffusion-limiting current densities of -1.87 and -2.74 mA center dot cm(-2), respectively. Both materials present, however, better tolerance to methanol crossover when compared to Pt/C and good stability. Regarding OER performance, MoS2@MWNT exhibits promising results, with eta(10) and j(max) of 0.55 V and 17.96 mA center dot cm(-2), respectively. The fabrication method presented here is cost-effective, robust and versatile, opening the doors for the optimization of electrocatalysts' performance.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 15