A New Member of Electrocatalysts Based on Nickel Metaphosphate Nanocrystals for Efficient Water Oxidation

High-performance electrocatalysts are desired for electrochemical energy conversion, especially in the field of water splitting. Here, a new member of phosphate electrocatalysts, nickel metaphosphate (Ni₂ P₄ O₁₂ ) nanocrystals, is reported, exhibiting low overpotential of 270 mV to generate the current density of 10 mA cm^-2 and a superior catalytic durability of 100 h. It is worth noting that Ni₂ P₄ O₁₂ electrocatalyst has remarkable oxygen evolution performance operating in basic media. Further experimental and theoretical analyses demonstrate that N dopant boosts the catalytic performance of Ni₂ P₄ O₁₂ due to optimizing the surface electronic structure for better charge transfer and decreasing the adsorption energy for the oxygenic intermediates.