Few-Layered Trigonal WS2 Nanosheet-Coated Graphite Foam as an Efficient Free-Standing Electrode for a Hydrogen Evolution Reaction

Xiaomeng Guo; Junyi Ji; Quanguo Jiang; Lili Zhang; Zhimin Ao; Xiaobin Fan; Shaobin Wang; Yang Li; Fengbao Zhang; Guoliang Zhang; Wenchao Peng

doi:10.1021/acsami.7b06613

Few-Layered Trigonal WS₂ Nanosheet-Coated Graphite Foam as an Efficient Free-Standing Electrode for a Hydrogen Evolution Reaction

ACS Appl Mater Interfaces. 2017 Sep 13;9(36):30591-30598. doi: 10.1021/acsami.7b06613. Epub 2017 Sep 1.

Authors

Xiaomeng Guo¹, Junyi Ji², Quanguo Jiang³, Lili Zhang⁴, Zhimin Ao⁵, Xiaobin Fan¹, Shaobin Wang⁶, Yang Li¹, Fengbao Zhang¹, Guoliang Zhang¹, Wenchao Peng¹

Affiliations

¹ School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China.
² School of Chemical Engineering, Sichuan University , Chengdu, Sichuan 610065, China.
³ College of Mechanics and Materials, Hohai University , Nanjing 210098, China.
⁴ Institute of Chemical and Engineering Sciences , A*STAR, 1 Pesek Road, Jurong Island 627833, Singapore.
⁵ Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology , Guangzhou 510006, China.
⁶ Department of Chemical Engineering, Curtin University , Perth, Western Australia 6845, Australia.

PMID: 28849902
DOI: 10.1021/acsami.7b06613

Abstract

Few-layered tungsten disulfide (WS₂) with a controlled-phase ratio (the highest trigonal-phase ratio being 67%) was exfoliated via lithium insertion. The exfoliated WS₂ nanosheets were then anchored onto three-dimensional (3D) graphite foam (GF) to fabricate free-standing binder-free electrodes. The 3D GF can increase the interfacial contact between the WS₂ nanosheets and the electrolyte and facilitate ion transfer. Without the nonconductive binder, an intimate contact between the WS₂ and GF interface can be created, leading to the improvement of electrical conductivity. In comparison to the pure WS₂ nanosheets, the overpotential for a hydrogen evolution reaction is significantly decreased from 350 mV to 190 mV at 10 mA/cm², and no deactivation occurs after 1000 cycles. The density functional theory computations reveal that the efficient catalytic activity of the trigonal-phase WS₂/GF electrode is attributed to the lower Gibbs free energy for H* adsorption and higher electrical conductivity.

Keywords: binder-free electrode; graphite foam; hydrogen evolution; mixed phase; tungsten disulfide.