Fe<sup>2+</sup>/Fe<sup>3+</sup> Cycling for Coupling Self‐Powered Hydrogen Evolution and Preparation of Electrode Catalysts
Chang Chen, Zhengqian Fu, Fenggang Qi, Yafeng Chen, Ge Meng, Ziwei Chang, Fantao Kong, Libo Zhu, Han Tian, Haitao Huang, Xiangzhi Cui, Jianlin Shi
Abstract
Abstract A novel Zn−Fe flow battery featuring an Fe 3+ reduction reaction (Fe 3+ RR)‐coupled zinc oxidation, and an Fe 2+ oxidation reaction (Fe 2+ OR)‐coupled hydrogen evolution reaction (HER) system as well, was established. This battery is capable of driving two Fe 2+ OR‐coupled HER systems in series based on the above Fe 2+ /Fe 3+ cycling, for efficient self‐powered hydrogen evolution. Meanwhile, this Fe 2+ /Fe 3+ cycling enables the preparation of a multifunctional catalyst, Pt‐3@SXNS (siloxene nanosheet), by the Fe 2+ OR‐promoted dispersion of Pt nanoparticles on SXNS; alternatively, this support could be obtained by Fe 3+ RR‐assisted exfoliation using Fe 3+ from the anolyte of Fe 2+ OR‐coupled HER. The Pt‐3@SXNS catalyst exhibits excellent catalytic activities toward Fe 3+ RR in the Zn−Fe flow battery, HER, and Fe 2+ OR in the electrolyzer, which is attributed to the strong electronic interaction between Pt and Si. This work offers a new strategy for energy storage and low‐cost hydrogen production from acidic wastewater.