FeCo66.7Ni33.3B Nanoparticles Integrated on Vertically Aligned Boron-Doped Graphene Array as Efficient Electrocatalyst for Overall Water Splitting in Wide pH Range

FeCoxNiyB nanoparticles with tuned cationic ratio integrated on Vertically Aligned Boron-doped Graphene Array (FeCoxNiyB@B-VG) electrocatalysts towards water splitting are successfully prepared by electroless plating. For a specific composition, FeCo66.7Ni33.3B@B-VG electrocatalyst exhibits the highest electrocatalytic activity towards hydrogen evolution reaction, with low overpotentials of 125 and 157 mV at η10 and small Tafel slopes of 52 and 47 mV dec−1 in 1.0 M KOH and 0.5 M H2SO4 solution, respectively. FeCo66.7Ni33.3B@B-VG electrocatalyst displays remarkable catalytic activity towards oxygen evolution reaction by showing low overpotentials of 200 and 569 mV at η10 and small Tafel slopes of 34 and 225 mV dec−1 in 1.0 M KOH and 0.5 M H2SO4 solution, respectively. The result of stability test exhibits that FeCo66.7Ni33.3B@B-VG electrocatalyst has long-term stability for at least 10 h towards water splitting in a wide pH range. And the faraday efficiency of FeCo66.7Ni33.3B@B-VG towards water splitting is around 90%. This study helps to explore the effect of variable cationic ratio in the fabrication of non-noble electrocatalyst to achieve enhanced electrocatalytic activity for water splitting in a wide pH range.