Mild construction of an Fe-B-O based flexible electrode toward highly efficient alkaline simulated seawater splitting

Chengyu Fu; Jinli Fan; Yiran Zhang; Haiyang Lv; Dingkun Ji; Weiju Hao

doi:10.1016/j.jcis.2022.12.104

Mild construction of an Fe-B-O based flexible electrode toward highly efficient alkaline simulated seawater splitting

J Colloid Interface Sci. 2023 Mar 15:634:804-816. doi: 10.1016/j.jcis.2022.12.104. Epub 2022 Dec 21.

Authors

Chengyu Fu¹, Jinli Fan¹, Yiran Zhang¹, Haiyang Lv¹, Dingkun Ji², Weiju Hao³

Affiliations

¹ School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, PR China.
² Institute of Molecular Medicine (IMM), School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, PR China.
³ School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, PR China. Electronic address: wjhao@usst.edu.cn.

PMID: 36565622
DOI: 10.1016/j.jcis.2022.12.104

Abstract

It is essential to construct self-supporting electrodes based on earth-abundant iron borides in a mild and economical manner for grid-scale hydrogen production. Herein, a series of highly efficient, flexible, robust, and scalable Fe-B-O@FeB_x modified on hydrophilic cloth (denoted as Fe-B-O@FeB_x/HC, 10 cm × 10 cm) are fabricated by mild electroless plating. The overpotentials and Tafel slope values for the hydrogen and oxygen evolution reactions are 59 mV and 57.62 mV dec^-1 and 181 mV and 65.44 mV dec^-1, respectively; only 1.462 V is required to achieve 10 mA cm^-2 during overall water splitting (OWS). Fe-B-O@FeB_x/HC maintains its high catalytic activity for more than 7 days at an industrial current density (400 mA cm^-2), owing to the loosened popcorn-like Fe-B-O@FeB_x that is firmly loaded on a 2D-layered and mechanically robust substrate along with its fast charge and mass transfer kinetics. The chimney effect of core-shell borides@(oxyhydro)oxides enhances the OWS performance and protects the inner metal borides from further corrosion. Moreover, the flexible Fe-B-O@FeB_x/HC electrode has a low cost for grid-scale hydrogen production ($2.97 kg^-1). The proposed strategy lays a solid foundation for universal preparation, large-scale hydrogen production and practical applications thereof.

Keywords: Alkaline simulated seawater splitting; Earth-abundant FeB(x); Electroless plating; Flexibility; Low-cost hydrogen production.