Polyoxometallates@zeolitic-imidazolate-framework derived bimetallic tungsten-cobalt sulfide/porous carbon nanocomposites as efficient bifunctional electrocatalysts for hydrogen and oxygen evolution. (10th January 2020)

• Record Type: Journal Article
• Authors: Huang, Zheng; Yang, Zhuxian; Hussain, Mian Zahid; Chen, Binling; Jia, Quanli; Zhu, Yanqiu; Xia, Yongde
• Is Part Of: Electrochimica acta. Volume 330(2019)
• Publication Date: 2020-01-10
• Subjects: Electrocatalyst -- Hydrogen evolution reaction -- Oxygen evolution reaction -- Zeolitic imidazolate frameworks -- Polyoxometalate; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.135335
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Hydrogen is one of the most promising sustainable energy among numerous new energy resources. Electrocatalytic water splitting for H2 generation is a clean and sustainable approach due to the use of widely existed water as resource. The searching for efficient and low-cost non-precious metal based electrocatalysts for water splitting, including both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), still remains a great challenge. In this work we report a simple method that utilizes the one-pot in-situ synthesized POMs@ZIFs (POMs = Polyoxometallates, ZIFs = Zeolitic imidazolate frameworks) as precursor for the production of WS2 /Co1-x S/N, S co-doped porous carbon nanocomposite as efficient electrocatalysts. These precursors POMs@ZIFs can effectively prevent the agglomeration of metal compound particles during heat treatment and lead to homogeneous dispersion of metal active sites within carbon matrix. The resulting bimetallic Co–W sulfide/heteroatom doped porous carbon composites show significant improvement in electrocatalytic activity towards both OER (Tafel slop of 53 mV dec −1 with overpotential of 0.365 V @10 mA cm −2 current density in 1 M KOH solution) and HER (Tafel slop of 64 mV dec −1 with overpotential of −0.250 V @−10 mA cm −2 current density in 0.5 M H2 SO4 solution). This work opens up a new way to obtain low cost bifunctional electrocatalysts towards both OER and HER in water splitting. Graphical abstract: Image 1 Highlights: WS2/Co1-xS/porous carbon materials were facile prepared via one-step carbonization of POM@ZIFs. Bimetallic Co–W sulfide nanoparticles are uniformly embedded in porous carbon matrix. The nanocomposites are efficient electrocatalysts for both HER and OER in water splitting.