Benzylamine oxidation boosted electrochemical water-splitting: Hydrogen and benzonitrile co-production at ultra-thin Ni2P nanomeshes grown on nickel foam

Abstract

In this work, ultra-thin Ni2P nanomeshes (1.9 nm thickness) on nickel foam (NF) substrate (denoted as Ni2P-UNMs/NF) are successfully achieved through phosphidation treatment using ultra-thin Ni(OH)2 nanomeshes on NF substrate (denoted as Ni(OH)2-UNMs/NF) as reaction precursor. Because of the sufficient active sites in edge of the holes, high specific surface area, porous framework and high conductivity of NF substrate, Ni2P-UNMs/NF nanocomposites show the outstanding activity for both hydrogen evolution reaction (HER) and benzylamine oxidation reaction (BOR) in alkaline electrolyte. Importantly, Ni2P-UNMs/NF nanocomposites can directly act as a bifunctional electrocatalyst for the electrochemical water-splitting in two electrode system in the presence of benzylamine, which only requires an electrolysis voltage of 1.41 V to achieve the 10 mA cm-2 current density in alkaline electrolyte, accompanying with H2 production at cathode and value-added benzonitrile production at anode. Obviously, the BOR boosted electrochemical water-splitting provides an energy-saving and cost-competitive H2 production method.