Oxygen Nucleation of MoS2 Nanosheet Thin Film Supercapacitor Electrodes for Enhanced Electrochemical Energy Storage

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Shi Nee Lou
  • Melvin Choon Heng See
  • Sean Lim
  • Neeraj Sharma
  • Jason Scott
  • Da-Wei Wang
  • Rose Amal

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)2882-2891
Journal / PublicationChemSusChem
Volume14
Issue number14
Online published20 May 2021
Publication statusPublished - 22 Jul 2021

Abstract

A direct thin film approach to fabricate large-surface MoS2 nanosheet thin film supercapacitors using the solution-based diffusion of thiourea into an anodized MoO3 thin film was investigated. A dense MoS2 nanosheet thin film electrode (D-MoS2) was obtained when the anodized MoO3 thin film was processed in a low thiourea solution concentration, whereas a highly porous MoS2 nanosheet thin film electrode (P-MoS2) was formed at a higher thiourea solution concentration. The charge storage performances of the D-MoS2 and P-MoS2 thin films displayed an unusual increase in capacitance on extended cycling, leading to a capacitance as high as around 5–8 mF cm−2. X-ray diffraction and cross-sectional microscopy revealed the capacitance enhancements of the MoS2 supercapacitors are attributable to the nucleation of a new MoS2-xOx phase upon cycling. For the D-MoS2 nanosheet thin film, the formation and growth of the MoS2-xOx phase during cycling was accompanied by a volumetric expansion of the MoS2 layer. For the P-MoS2 thin film, the nucleation and growth of the MoS2-xOx phase occurred in the pores of the MoS2 layer. The propagation of the MoS2-xOx phase also shifted the charge storage process in both films from a diffusion-limited process to a capacitive-dominant process.

Research Area(s)

  • 2D materials, anodization, MoS2, supercapacitor, thin film

Citation Format(s)

Oxygen Nucleation of MoS2 Nanosheet Thin Film Supercapacitor Electrodes for Enhanced Electrochemical Energy Storage. / Nee Lou, Shi; Choon Heng See, Melvin; Lim, Sean; Sharma, Neeraj; Scott, Jason; Wang, Da-Wei; Amal, Rose; Hau Ng, Yun.

In: ChemSusChem, Vol. 14, No. 14, 22.07.2021, p. 2882-2891.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review