Construction of efficient bismuth/boron-based flexible electrodes in organic media toward neutral hydrogen evolution

Abstract

Preparing highly efficient, low-cost and stable catalysts to produce hydrogen in neutral electrolytes is a major challenge due to sluggish kinetics, low conductivity and a complex hydrogen adsorption–desorption process. Herein, a series of bismuth/boron-based materials are successfully anchored on different kinds of flexible substrates via simple and mild electroless plating in organic media, forming a binder-free porous structure that is conducive to the hydrogen evolution reaction (HER). The bismuth/boron-based (Bi–B) electrodes not only have high intrinsic activity, rapid mass transfer capability, and large specific surface area, but can also be tightly loaded on the surface of the flexible, curved and folded substrate with a uniform distribution. In particular, the Bi–B/BiB₃O₆@HC electrode achieves highly efficient catalytic performances with an overpotential of 88.5 mV at 10 mA cm⁻² and a Tafel slope of 53.8 mV dec⁻¹ in neutral electrolyte solution (1.0 M PBS). The catalytic electrode with outstanding durability can electrolyze continuously for more than 36 h with negligible loss at an industrial-grade current density of 100 mA cm⁻². The series of Bi–B-based catalytic electrodes also maintain high catalytic activities in alkaline simulated seawater. This strategy provides theoretical support for developing robust, novel and inexpensive catalytic electrodes for hydrogen production in both neutral and alkaline seawater.