Ru, B Co-doped hollow structured iron phosphide as highly efficient electrocatalyst toward hydrogen generation in wide pH range

Abstract

Electrocatalytic hydrogen evolution reaction (HER), as a promising green and sustainable method for hydrogen production, has received widespread attention, and designing efficient and stable electrocatalysts is one of the keys to accelerating the development of the hydrogen economy. Herein, B and Ru co-doped iron hollow spheres (H-B/Ru-FeP) are synthesized by ambient boronation, low-temperature phosphorization and acid leaching processes. The hollow porous structure and doping strategy favor enhancing the electrocatalytic kinetics by exposing numerous active sites, building rich mass transport channels and providing efficient adsorption/desorption of reactant/intermediates. Then, the as-synthesized H-B/Ru-FeP exhibits excellent electrocatalytic performance toward HER with low overpotentials of 29 mV, 86 mV, and 110 mV, to drive the current density of 10 mA cm⁻² in acidic, neutral and alkaline electrolytes, respectively. The electrolyzer is assembled with H-B/Ru-FeP as the cathode and NiFe foam as the anode, requiring a low cell voltage of 1.54 V to drive 10 mA cm⁻². This work opens a novel approach to exploit hollow structures for energy conversion and storage applications.