Electronic structure modulation of isolated Co-N4 electrocatalyst by sulfur for improved pH-universal hydrogen evolution reaction

Palani Sabhapathy, Indrajit Shown*, Amr Sabbah, Putikam Raghunath, Jeng Lung Chen, Wei Fu Chen, Ming Chang Lin, Kuei Hsien Chen, Li Chyong Chen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Exploring an efficient platinum group metal (PGM) free electrocatalyst with superior activity and stability for hydrogen evolution reaction (HER) in a wide pH range is desirable for low-cost hydrogen production. Here, we report atomically dispersed cobalt on nitrogen and sulfur co-doped graphene (N-Co-S/G) for HER. Remarkably, the prepared N-Co-S/G electrocatalyst shows a small overpotential of 67.7 mV vs. reversible hydrogen electrode (RHE) at a current density of 10 mA cm−2 and exceptional durability over 100 h at 10 mA cm−2 under acidic conditions. Moreover, we found that the HER activity of N-Co-S/G is close to 20% Pt/C at all pH levels (0–14) and superior activity at high current density (>100 mA cm−2). Experimental and theoretical calculations reveal that the S atom in N-Co-S/G form Co-S bond, resulting new Co-N3S1 active site, which optimizes Gibbs free energy for hydrogen adsorption (∆GH*) close to zero, while water adsorption and dissociation enhanced by S modulation for neutral and basic media HER.

Original languageEnglish
Article number105544
JournalNano Energy
Volume80
DOIs
StatePublished - Feb 2021

Keywords

  • Atomic cobalt
  • Electronic structure
  • Graphene
  • Hydrogen evolution reaction (HER)
  • Nitrogen and sulfur co-doped
  • Nonprecious electrocatalyst

Fingerprint Dive into the research topics of 'Electronic structure modulation of isolated Co-N4 electrocatalyst by sulfur for improved pH-universal hydrogen evolution reaction'. Together they form a unique fingerprint.

Cite this