Synthesis of heteroatom incorporated porous carbon encapsulated Fe-doped Co9S8 as an efficient bifunctional electrocatalyst for overall water splitting. (April 2023)

• Record Type: Journal Article
• Authors: Khan, Javid; Liu, Heng; Xiao, Jiamin; Zhu, Yanlin; Hayat, Asif; Ullah, Hameed; Ahmed, Gulzar; Zhang, Handong; Sun, Yanyan; Han, Lei
• Is Part Of: Journal of physics and chemistry of solids. Volume 175(2023)
• Publication Date: 2023-04
• Subjects: Fe–doped Co9S8 -- Heteroatom doping -- Porous carbon -- Bifunctional electrocatalysts -- Overall water splitting; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2023.111220
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Doping metal ions into cobalt sulfide is a promising strategy to improve its performance as a cheap, green, highly active and sustainable electrocatalyst for overall water splitting. Herein, cauliflower-like, noble metal-free bifunctional electrocatalysts composed of S, N, and O atoms co-incorporated porous carbon (SNOPC) encapsulated Fe doped Co9 S8 nanoparticles are successfully synthesized by direct pyrolysis of S, Co, and Fe-based polypyrrole ( S – Co –Fe-PPYs) precursors for efficient overall water splitting. Specifically, the optimal catalyst (Fe0-33 -Co9 S8 @SNOPC) shows excellent electrocatalytic performance in an alkaline electrolyte, requiring ultra-low overpotentials of 275 and 258 mV to reach a current density of 10 mA cm −2 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, with exceptional stability for 50 h. Furthermore, when applied for overall water splitting as a bifunctional electrolyzer, it generates a current density of 10 mA cm −2 at an extremely low cell voltage of 1.595 V. The exceptional electrocatalytic activity of Fe0-33 -Co9 S8 @SNOPC can be credited to the synergistic effect produced by Fe doped Co9 S8 core and multi-atom incorporated porous carbon shell. Graphical abstract: Cauliflower-shaped Fe-doped Co9 S8 embedded in S, N, and O co-doped porous carbon (SNOPC) materials have been prepared by direct pyrolysis of S, Co and Fe-based polypyrrole ( S – Co –Fe-PPYs) precursors as noble-metal-free bifunctional electrocatalyst towards efficient overall water splitting under alkaline condition. Image 1 Highlights: Fe-doped Co9 S8 embedded in S, N, and O-doped carbon were obtained by pyrolysis of S, Co and Fe-containing polypyrrole. The optimal catalyst has low overpotential of 275 and 258 mV at the current density of 10 mA cm −2 for the OER and HER. Low voltage of 1.595 V is needed at the current density of 10 mA cm −2 for overall water splitting. The synergistic effect between Fe-doped Co9 S8 and heteroatom-doped carbon contributes to remarkable catalytic activity.