Electrodeposition of Co/CoO nanoparticles onto graphene for ORR electrocatalysis: a study based on micro-X-ray absorption spectroscopy and X-ray fluorescence mapping

Abstract

Electrodeposition of graphene-supported Co for ORR electrocatalysts from an acetonitrile solution has been studied by a multi-technique approach, combining a suite of spectroscopic methods with electrochemical measurements, allowing a molecular-level understanding of potentiostatic and pulsed-potential plating processes from the organic solvent onto a freestanding graphene film. The formation of the graphene film by the light-scribe approach has been monitored by Raman spectroscopy; the electrodeposition process has been clarified by cyclic voltammetry and the compositional and chemical-state distribution of Co have been investigated ex situ by soft X-ray absorption spectroscopy and fluorescence mapping, showing that both spatial distribution and valence state are homogeneous and independent of the local current density. The deposit consists in micrometric aggregates of Co/CoO nanoparticles with diameter ca. 30 nm (pulsed) and 200 nm (potentiostatic deposition). Potentiostatic deposition allows to obtain better ORR electrocatalytic perfomance in terms of nnumber of transferred electrons, onset/ half-wave potential and current density.


Tutti gli autori

  • Bozzini B. , Bocchetta P. , Gianoncelli A. , Mele C. , Kiskinova M.

Titolo volume/Rivista

ACTA CHIMICA SLOVENICA


Anno di pubblicazione

2014

ISSN

1318-0207

ISBN

Non Disponibile


Numero di citazioni Wos

9

Ultimo Aggiornamento Citazioni

28/04/2018


Numero di citazioni Scopus

9

Ultimo Aggiornamento Citazioni

28/04/2018


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile