Nanohybridization of MoS2 with Layered Double Hydroxides Efficiently Synergizes the Hydrogen Evolution in Alkaline Media

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

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Author(s)

  • Jue Hu
  • Chengxu Zhang
  • Lin Jiang
  • He Lin
  • Yiming An
  • Dan Zhou
  • Shihe Yang

Detail(s)

Original languageEnglish
Pages (from-to)383-393
Journal / PublicationJoule
Volume1
Issue number2
Online published13 Sep 2017
Publication statusPublished - 11 Oct 2017

Abstract

SUMMARY

Hydrogen evolution reaction (HER) on earth-abundant molybdenum disulfide (MoS2) in acidic media is a robust process, but is kinetically retarded in alkaline media. Thus, improving the sluggish kinetics for HER in alkaline media is crucial for advancing the performance of water-alkali electrolyzers. Here, we demonstrate a dramatic enhancement of HER kinetics in base by judiciously hybridizing vertical MoS2 sheets with another earth-abundant material, layered double hydroxide (LDH). The resultant MoS2/NiCo-LDH hybrid exhibits an extremely low HER overpotential of 78 mV at 10 mA/cm2 and a low Tafel slope of 76.6 mV/dec in 1 M KOH solution. At the current density of 20 mA/cm2 or even higher, the MoS2/NiCo-LDH composite can operate without degradation for 48 hr. This work not only brought forth a cost-effective and robust electrocatalyst, but more generally opened up new vistas for developing high-performance electrocatalysts in unfavorable media recalcitrant to conventional catalyst design.

Context & Scale

Central to electrocatalysis are efficient and robust electrocatalysts composed of earth-abundant elements, which are urgently needed for realizing low-cost and high-performance energy conversion devices. Earth-abundant MoS2 has emerged as a promising hydrogen evolution reaction (HER) catalyst with high activity and durability. However, such a high HER performance is only limited to acidic media, the kinetics becoming rather sluggish in alkaline media. Besides the hydrogen (Had) adsorption energy, there should be a second descriptor for gauging the HER catalytic activity in alkaline media, namely the binding of hydroxyl species, because here H has to be discharged from water instead of from hydronium ions in acidic media. This work is the first to successfully design and fabricate a synergistic hybrid catalyst system, which is composed of MoS2 as an H-acceptor and OER-efficient layered double hydroxide as an OH acceptor, for dramatically facilitating the HER process in alkaline media. This work is the first to successfully design and fabricate a synergistic hybrid catalyst system, which is composed of MoS2 as an H-acceptor and OER-efficient layered double hydroxide as an OH acceptor, for dramatically facilitating the rate-determining water dissociation step and thus the overall HER catalysis in alkaline media.

Research Area(s)

  • dual-pathway kinetic model, free energy diagram, hydrogen evolution reaction, kinetics analysis, layered double hydroxide, MoS2, synergistic hybrid system, water dissociation

Citation Format(s)

Nanohybridization of MoS2 with Layered Double Hydroxides Efficiently Synergizes the Hydrogen Evolution in Alkaline Media. / Hu, Jue; Zhang, Chengxu; Jiang, Lin; Lin, He; An, Yiming; Zhou, Dan; Leung, Michael K.H.; Yang, Shihe.

In: Joule, Vol. 1, No. 2, 11.10.2017, p. 383-393.

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