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

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.