P-doped Ni-Fe-S Nanoflowers as a Highly Efficient Electrocatalyst for Oxygen Evolution Reaction

초록

Water splitting system has received significant attention as a possible approach to due to their potential to generate clean and sustainable energy sources. However, the kinetically sluggish process of oxygen evolution reaction (OER) still acts as bottleneck in the water splitting system. Recently, phosphosulfide and P-doped sulfide materials have been regarded as an efficient electrocatalysts for overall water splitting. However, practical application of these materials is severely limited by their complex synthesis method. Herein, we fabricated pyrite type P-doped nickel-iron sulfide (P-doped Ni-Fe-S) nanoflower electrocatalyst for OER with hierarchically porous structure through successive hydrothermal and low temperature phosphosulfidation method with P2S5. Owing to the well-tuned electronic environment by P doping and hierarchical 3D architecture, P-doped Ni-Fe-S nanoflowers show superior OER activity with the overpotential of 264.4 mV to deliver current density of 10 mA cm-2, an extremely low Tafel slope of 48 mV dec-1, and outstanding durability over 20 h without obvious degradation in 1 M KOH electrolyte. The facile preparation procedure can pave a new way to achieve electrocatalyst for energy storage and conversion such as rechargeable battery, supercapacitor, and water splitting.