A novel ball-in-ball hollow oxygen-incorporating cobalt sulfide spheres as high-efficient electrocatalyst for oxygen evolution reaction

• Published in: Chinese chemical letters Vol. 32; no. 2; pp. 755 - 760
• Main Authors: Li, Yurong, Guo, Qifei, Jiang, Yimin, Shen, Wei, Li, Ming, He, Rongxing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-2021; College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
• Subjects: Electrocatalyst; Kirkendall effect; Oxygen doped; Oxygen evolution reaction; Sulfides; Kirkendall effect; Sulfides; Electrocatalyst; Oxygen evolution reaction; Oxygen doped
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2020.05.012

Introduction of oxygen and sulphur into the novel oxygen-containing amorphous cobalt sulfide ball-in-ball hollow spheres (Co-S-O BBHS) catalyst prepared by anion exchange and Kirkendall effect greatly changes their electronic structure and strengthens the adsorption of *O (adsorbed O species on catalyst surface) intermediate, which leads to outstanding OER activity.
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Transition-metal chalcogenides with hollow nanostructure, especially cobalt sulfides, are considered as the most promising non-precious metal catalysts for oxygen evolution reaction. However, it is difficult to synthesize oxygen-containing cobalt sulphides with hollow structure due to the different physical/chemical properties between metal sulfides and metal cobalts. Herein, we report a novel oxygen-containing amorphous cobalt sulfide ball-in-ball hollow spheres (Co-S-O BBHS) synthesized by an anion exchange method. Taking advantage of the ball-in-ball hollow structure, the amorphous Co-S-O BBHS shows superior oxygen evolution reaction (OER) electrocatalytic performance with a low overpotential of 285 mV at 10 mA/cm2, small Tafel slope of 49.67 mV/dec, high Faraday efficiency of 96%, and satisfied durability. Experiments and DFT calculations demonstrate that the introduction of oxygen and sulfur modulates the electronic structure of Co-S-O BBHS, thus enhancing the adsorption of *O (adsorbed O species on catalyst surface) intermediate, which greatly boosts the catalytic activity towards OER. This work provides a new strategy for controllable synthesis of complex hollow structures of transition-metal chalcogenides for OER.