An Iron-Group Metal Boride/Boron-Doped Vertically Oriented Graphene as Efficient Catalyst for Overall Water Splitting in a Wide pH Range

Abstract

Exploring earth–abundant and non–noble metal bifunctional stable electrocatalysts with excellent catalytic performance for overall water splitting in a wide pH range is greatly desirable and challenging. Herein, a newly designed Fe–Co–Ni–B/boron−doped vertically oriented graphene (Fe–Co–Ni–B/BVG) electrocatalyst is fabricated via single−step electrodeposition method. The as–synthesized electrocatalyst exhibits excellent hydrogen evolution reaction (HER) activities with low overpotentials of 41, 140, and 168 mV at a current density of 10 mA cm−2 in 1.0 M KOH, 0.5 M H2SO4, and 1.0 M phosphate buffer solutions (PBS), respectively at all pH values (pH 0–13.8). Fe–Co–Ni–B/BVG electrocatalyst also exhibits excellent oxygen evolution reaction (OER) activities with overpotentials of 163 and 110 mV at a current density of 10 mA cm−2 in 1.0 M KOH and 1.0 M PBS solutions, respectively. This electrocatalyst also shows prominent electrochemical durability (over more than 10 h). This study may provide a facile design for the fabrication of cost–effective and non–noble metal bifunctional electrocatalysts material for overall water splitting withstand in different pH conditions.